External water supply systems. What is an external water supply network. Groundwater intake facilities

Any water supply network is presented as a complex of structures and elements that provide industrial and domestic facilities with water.

pipes made of polypropylene, steel, LDPE;
reservoir for water intake;
pump;
manhole with water shut-off fittings;
storage tanks and water purification system.

In the process of arranging external water supply networks, the established norms and requirements of SNiP are observed. External water supply is classified into the following types (by purpose):

household;
fire fighting;
production;
irrigation;
negotiable.

According to the method of piping, the network can be laid according to several schemes:

dead end - used to provide water to small objects;
ring - designed for uninterrupted supply of fluid. For its arrangement, a large number of consumables are used.

Experts distinguish between the following pipe laying methods:

Ground.
Underground.
Trench.
Trenchless.

System device

For successful and trouble-free operation of the system, it is recommended to carry out the correct structural arrangement of the pipeline. More often the system is equipped with factory pipes. There are certain requirements for the arrangement of water supply:

strength to withstand external and internal loads;
tightness;
smooth surface of the inner walls, which reduces the loss of pressure due to friction;
durability.

The consumables used must be quickly and easily assembled at the site of the system. The water supply network must meet the requirements of increased efficiency. Pressure pipes are selected taking into account the resistance of water. To calculate the working pressure, the footage of the entire network, the diameter of the pipeline used are taken into account. Calculations can be carried out independently or by contacting specialists for help.

Taking into account the requirements for the installation of consumables, the pipes must have the required strength. This will allow them to withstand the pressure exerted by the soil, including the deflection of their own weight. In this case, the possible loads exerted by the transport are taken into account. The tightness of pipes and joints is an important condition for the successful and economical operation of the network. If the tightness is not observed, excess fluid costs are observed, which contributes to an increase in the cost of operating the water supply network.

Soil erosion and a serious accident on the highway can lead to water leakage from the system. To equip the system under consideration, in order to serve any object, pipes are used, the choice of which depends on the following criteria:

volume of liquid supplied;
soil type;
working internal pressure.

Therefore, different types of pipes can be used for water supply systems, taking into account the conditions of the area where construction work is being carried out. For the improvement of external water supply, steel, reinforced concrete and cast iron pipes are used. It is possible to lay a pipeline from synthetic pipes. To make the right choice, it is first recommended that you familiarize yourself with the performance characteristics of all types of pipes.

Types of plumbing

Before conducting external water supply, it is recommended to determine its type. According to the methods of transporting water to the final object, the water supply network can be technical. In this case, water is used only for production. You can't drink it. To save money, technical networks are partially cleared. This allows you to reuse the waste water resource.

The fire network is equipped for fire extinguishing. Such systems are equipped with special equipment and a hydrant. If it is necessary to save money, when performing laying work, the fire system is combined with a technical, household or dead-end scheme. For installation work, it is necessary to be guided by the principles of fire safety. Therefore, before laying the pipeline, you need to obtain permission from the relevant authorities. Installation work is carried out independently or with the help of professionals.

To use water in everyday life, a household system is being equipped. Water supplied under this scheme is used for drinking. Before laying the pipeline, a plan is developed for the primary treatment of the liquid. For this, special stations or filters can be used.

Plumbing schemes

To lay a pipeline for a future water supply system, a scheme is being prepared. It indicates all the elements of the network, the main technical characteristics of the pipeline. Conduits are used to transport water from the source to the desired object. They can consist of 2 or more pipelines, which are parallel to each other.

To supply water to the place of consumption, an external water supply system is equipped. Water supplied to specific points of water intake within the facility requires the arrangement of an internal water supply. Taking into account the configuration, the external network is mounted in a closed or branched type.

With the help of a ring network, a constant supply of liquid is ensured. But for the arrangement of such a system, a large amount of consumables, including fittings, fittings, will be required.

A closed network is effective if you need to provide water to a small household. The dead-end system is equipped at facilities where there are interruptions in water supply or frequent accidents occur.

The outdoor water supply system consists of main and secondary lines. A separate pipeline is required for process water, which must not be mixed with potable water. In this case, it is recommended to make 3 schemes.

Separately, a drawing is prepared for technical and drinking pipelines. Additionally, they make a general scheme of the system. If the drawing is done independently, it is recommended to use graph paper. In the absence of skills in drawing up diagrams, it is recommended to consult with specialists.

Water from the water supply under pressure enters the internal network. For this, a special input is provided in the soil, presented in the form of a pipeline branch from the external network to the water metering unit or shutoff valves laid inside the serviced facility.

Taking into account the location of the distribution line in relation to the water points, a distinction is made between the upper and lower wiring of the water supply system. In the upper wiring, the main is located above the draw-off points, and in the lower one - below. The external network has low pressure, while the internal network requires high pressure. To do this, install a pump and a special tank.

The ring internal water supply network is being equipped for technological purposes. If it has 10 or more points, then it is connected to an external system using two or more inputs. The use of the dead-end scheme is limited.

The external water supply network is laid in the soil. In areas with permanent permafrost, water supply is carried out above the ground. To do this, prepare special supports that require subsequent thermal insulation. Mineral wool is used as a heater.

Mounting Features

Before laying a pipeline, consider the following criteria:

depth of soil freezing and pipe laying;
liquid temperature;
water supply mode.

If it is necessary to carry out the main pipeline, then the depth of the pipes is calculated individually. This takes into account the mode in which the system will operate. Calculations can be carried out independently or with the help of specialists. In any case, the value of the main indicator depends on the external loads exerted on the soil and the climatic conditions of the area.

The pipeline line corresponds to the relief of the land plot. When arranging the system, the slope that must be observed on level ground is taken into account. With the help of such a slope, it is possible to empty the network and exit air masses at the maximum points of the water supply. The last process proceeds with the help of plungers.

If fittings and fittings with special connections are used to equip the system, then brick or ready-made wells are equipped at the places of their installation. Their parameters depend on the dimensions of the reinforcement used and the depth of the network. The well can have a rectangular or round shape. Above the soil, the well is closed with a special hatch. It can be bought or made from cast iron.

When installing the internal system, the open method is followed. The pipeline is laid over building structures. This technical solution facilitates the installation and operation of the entire system. The laying of any water supply network can be done independently or with the help of professionals.

For laying use the level and other construction equipment. Upon completion of installation work, the system is checked for tightness. If leaks are detected, they are fixed as soon as possible. Only after repair work is it allowed to restart the water supply system.

Water is one of the main elements necessary to support the life of mankind and all life on our planet. In parallel with the natural water cycle, artificial water supply systems designed and built by people are actively involved in this process. Water supply systems are internal and external.

Function of outdoor water supply systems

External water supply networks are an important element of water supply systems, providing uninterrupted supply water for the population and businesses. The supply of resources through these systems, as a rule, is made from natural sources. Used as The groundwater(ground, artesian and springs), and surface water bodies (rivers, lakes, reservoirs).

Groundwater is usually fresh. Therefore, they are mainly used for consumer purposes. Surface water can be either fresh or saline. Such resources are used for technical purposes: in enterprises, in agriculture, etc.

Outdoor water supply systems supply cold and hot water.

Types of water supply networks

External water supply systems according to their purpose are divided into two types:

Central water supply.
Individual water supply.

The central water supply system provides simultaneous water supply to a large number of consumers. Used in cities and urban-type settlements. Pressure in such systems is formed when using water towers. For the uninterrupted supply of water (both cold and hot) in centralized systems, special utility services.

Individual water supply is designed for a small amount of consumers. May so provide for exclusively private use. In individual water supply, the use is common storage containers.

According to the design of the water supply system, there are:

Branched (dead end).
Ring.
Combined (simultaneously include the first and second options).

Design and layout of external networks

Designing an external water supply network is a very important and required process, without which the practical implementation of the upcoming construction work is impossible.

Three main design stages:

technical task;
project documentation;
working documentation.

Terms of Reference (TOR) is original document. It contains a list of all conditions for the organization of work, which determine the number of design stages. The ToR defines work limits, list of equipment and materials to be taken into account in the composition of the subsequent project documentation.

Project documentation is developed by the design organization in sufficient passing an examination volume. Project documentation is being carried out in accordance with Decree No. 87 of the Government of the Russian Federation.

Working documentation is developed by the design organization in sufficient for building volume.

When designing external water supply networks, it is worth considering the presence of other underground engineering networks. The location of the water supply system in relation to other possible engineering networks should provide the possibility of free access to them, if it becomes necessary to perform repair work. In case of damage to the water supply, it is important to exclude the possibility of undermining the foundations of nearby buildings.

On driveways, pipelines are laid strictly along the highway, in a straight line and parallel to the building line. All crossings of water networks should be carried out at an angle of 90°. The permissible minimum distance between the water supply and structures depends both on the characteristics of the water supply networks themselves (pipe diameter, operating pressure, etc.), and on the type of construction and foundation depth the buildings.

The main factors influencing the location of outdoor water supply networks:

Features of the terrain.
The presence of obstacles (railway, river, etc.).
Object layout.
Location and layout of residential areas, their size.
The presence of vegetation.

No less important is the component of the project - detailing, that is network diagram. On it by symbols applied equipment, shaped parts, fittings. When compiling it, first of all, the location of pipeline fittings and hydrants is determined. Gate valves must be located in a way that allows shut off the water supply to separate sections, without stopping its inlet to facilities that require continuous supply of water resources. Detailing is done schematically, not to scale. If necessary, individual nodes are drawn separately on a larger scale.

SNiP requirements for external water supply networks

Building codes and regulations (SNiP) have a number of requirements mandatory for implementation in the design and construction of external water supply networks. The main of these rules are listed below:

Due to the rapidly developing civilization and new technologies, it is possible that in the future there will be new types of water supply networks, new technologies for their construction. Accordingly, there will be a need to make certain amendments to building codes and regulations regarding plumbing systems. But, only some numbers will be adjusted. And the main task is to provide humanity with industrial and drinking water in conditions complete security- will remain unchanged.

Water supply and sewerage of construction sites is the most necessary invention of man.

Man is designed in such a way that he cannot do without water. At all times, people inhabited places near rivers, dug wells to gain access to this vital fluid. Subsequently, water supply systems began to be designed, which is necessary for human life, recreation and work. These systems must ensure high-quality uninterrupted supply of water in the required quantities and at any time, and comply with the SP Water supply to external networks and structures.

Simultaneously with water supply systems, sewage systems for receiving and processing water and human waste have also progressed.

Rules for laying communications

In order for people to live comfortably, household amenities should be located in the room where they are. Therefore, in addition to piping inside the building, the object must be connected to external communication networks. As in any locality where the construction of the facility is taking place, SNiP are a prerequisite for providing water and sewerage. Water supply external networks and structures:

permission and project for this type of construction work with the laying of external communications and water supply entry points to the house for connection to the internal plumbing network, as well as the sewerage outlet connected to the cleaning system;
compliance with the requirements for earthworks, control over hidden works and execution of technical supervision acts;
compliance with the requirements for network materials, their quality; networks must guarantee trouble-free operation of water supply and sanitation, correcting faults will lead to additional costs for the developer.

Such serious requirements are due to:

compliance with high-quality installation of networks and subsequent safe operation;
financial savings and trouble-free operation of the external water supply and sanitation network;
protection against damage to other communications laid in the ground, where work is carried out on laying networks;
the terms of environmental laws that aim to protect groundwater;
compliance with sanitary standards that do not allow polluting the areas where the construction site is located;
building regulations.

Main stages of work

The general stages of installation of external engineering networks for supplying water and draining waste water after the execution of project documentation and permits include:

Ground works for laying pipes.
Foundation device for laying pipes, backfilling the bottom with sand.
Installation of pipelines in trenches.
Installation of pipes by piercing the soil and horizontal drilling if it is impossible to dig a trench (under the road).
Installation of reinforced concrete, brick wells, chambers.
Installation of control and shut-off valves, fire hydrants and columns.
Backfilling the network with safe material, sand with compaction.
Restoration of the territory in the area of construction works, landscaping.
Registration of acts of work at all stages.
Preparation and connection to the central communications network or to internal plumbing wiring in the house with individual water supply and sanitation.
Preparation of a package of technical documentation and delivery of a construction site.

External water supply networks

Water supply systems are centralized in the form of an extensive city network, and autonomous if there is no central network for supplying water to houses. They must meet the requirements of SNiP External water supply networks.

Central networks consist of the following elements:

water intake (reservoir, lake, river, well);
stationary complex;
pumping station to provide the necessary pressure;
wells, places of connection of objects and shutoff valves.

Types of autonomous water supply

If there is no central water supply network nearby, and there is no connection to it, then water supply can be provided as follows. Drinking water can be delivered in containers for cooking and drinking. This is a temporary option for a transitional period until a permanent reliable water supply to the building is established.

You need to know that there is water everywhere in the earth. It does not depend on the location of your place. The only question is the depth of the layers of water and its quality. To get water and raise it to the surface, it is necessary to build a well or a deep well.

Outdoor systems - water supply and sewerage

There are many types of sewer networks used to drain wastewater from structures and buildings. When developing a project for a construction site, it is necessary to take into account SNiP Water supply and sewerage external networks:

purpose of the object: economic object or residential building;
seasonal, episodic, continuous operation of the house and sewerage networks;
system load, volume of drains, number of plumbing fixtures installed in the house, number of people living;
the terrain where the building is located;
system cost;
system design together with the outlet pipeline;
a system for processing, receiving and utilizing wastewater;
ratio of productivity, quality and price;
equipment, components and materials;
wastewater treatment quality;
service and guarantee of reliable operation.

Types of receiving sewage equipment

For an occasional or seasonal stay in the house, it is often enough to mount a dry closet. But this system is not able to ensure the removal of drains from the laundry room, shower room and kitchen. To do this, mount different containers for collecting wastewater. The advantages of such receivers include mobility, compactness and low maintenance.

For a long stay in the building, external sewage systems are installed - a cesspool, a waste tank, a septic tank, a deep cleaning system.

Cesspool for sewage and waste

The type of external sewage used earlier in the form of a cesspool was a good device where the construction of buildings was carried out, and there was no central sewerage. Today it is difficult to obtain permission to connect a new house to the existing sewerage system in a community. Therefore, such a device as a cesspool worked for a long time due to the simple structure, cheap maintenance and long-term operation.

In the modern period, a cesspool is sometimes built outside the city, near houses where people live seasonally. With the emergence of a large number of plumbing fixtures in homes and significant water consumption for various needs, the cesspool can no longer cope and needs to be cleaned frequently.

An alternative to pits - septic tanks

These are autonomous treatment plants and facilities, both industrial and home-made.

The following types of septic tanks have become the most popular:

Purifying type. They make it possible to collect and process wastewater, defending them in chambers with the help of bacteria.
Cumulative. They are made in the form of ordinary large tanks of different volumes, accumulating and storing wastewater until it is removed by special machines.

Homemade septic tanks are a system of several chambers in which solid waste is settled. According to the number of chambers, they are two or three-chamber. Tanks are made of concrete rings, bricks or monolithic. A mandatory requirement for septic tanks is tightness to prevent the entry of microorganisms into the soil and into the external environment.

Arrangement of septic tanks

For self-arrangement of a septic tank, the following factors must be considered:

type of soil in the territory;
the smallest distance from water intake on clay soils, as well as heavy soils - not less than 30 meters;
on sandy and sandy soils, the distance from the water intake is at least 60 meters.

Work is carried out in the following order:

1. Digging a pit of the required size.
2. Spilling the bottom with layers of rubble and sand.
3. Reinforcing mesh laying, concrete pouring.
4. Arrangement of receiving chambers, formwork, pouring of the wall with reinforcement, installation of concrete rings.
5. Sealing seams and joints.
6. Connecting pipes to a septic tank from an external sewer.
7. Arrangement of the locking device of the cameras.

Often a septic tank is equipped with a wastewater treatment device; only partial cleaning takes place in the sedimentation tanks. A filtration system is installed, consisting of drainage pipelines under a slope. Water through these pipes from the septic tank is distributed through the filter, and penetrating through the soil, it is purified.

Industrial cleaning

Such systems are made in such a way that they are easy to install, they are reliable in operation and do not pose a danger to the external environment. The industry produces a large number of different designs, according to the degree of purification, cost and other characteristics. Usually, firms install and configure their products themselves, and also give warranty certificates for equipment.

In areas where groundwater is at a shallow depth, it is impossible to install conventional septic tanks. Otherwise, you will often have to pump out drains with a special machine. In such a situation, the best option would be to install a deep cleaning system.

Such stations are highly efficient compared to a septic tank, and serve for large buildings. This equipment assumes a continuous supply of their electrical energy for the normal functioning of high-quality cleaning. The stations make it possible to purify wastewater by 98%, use reliable membranes and comply with SNiP Water Supply and Sewerage.

A good indicator of wastewater treatment equipment is that the system is a short time without drains. With a new intake, the process of biochemical reactions is restored for deep purification of wastewater coming from the public sewer.

List of pipes and accessories

Conclusion

In regulatory documents, you can find all the necessary provisions on external and internal communications and pipelines. This document makes it possible to prevent various errors in the construction of important facilities.

Water supply, in other words, water supply networks, is a closed system, consisting of many elements and structures, designed to provide premises with water. At the same time, the water supply itself consists of both external and internal networks. What is included in the external water supply networks, as well as the characteristics and features of the operation of the components will be disclosed in this article.

Consumables of external networks largely coincide with the material of internal ones, although they are required in a larger volume. Pipelines are a key component of outdoor networks. The material of modern pipelines is represented by a diverse range, from classic steel to modern polypropylene and polyethylene structures. To increase the pressure in external networks, pumping stations are used, since pumping in pipes is carried out under the required pressure from the source to consumers.

Shutoff valves and manholes are also placed on the pipeline line. Most modern systems use water treatment stations in outdoor networks. Such stations carry out additional purification of water, improving its quality and making it suitable for drinking. The composition of external networks may include water intake and water intake facilities. The former are required to draw water from a source, the latter to store water.

The purpose of external networks is different. The most common purpose is the transfer of drinking water, that is, domestic. There is also an external one, designed exclusively for extinguishing water. Industrial and technological external networks are designed for pumping non-potable water for technological needs. Irrigation and watering systems are needed for agricultural needs, caring for ornamental plants. There are also combined systems that combine several of the above purposes.

What is required before starting work?

At the design stage, it is necessary to take into account many norms in accordance with the norms of water supply - GOST and with SNiP standards related to water supply. There is a norm of separate distances between the details of external water supply networks and landscape elements. For example, the distance from the sewer to the water supply must be at least one meter, and the distance from the water/sewer pipes to the roadway boundary must be at least two meters.

In addition to the permit and the project, it will be necessary to obtain acts from the technical supervision for compliance with the requirements for excavation and hidden work.

In addition, it is important to comply with the quality of consumables to existing standards. Only the use of high-quality materials can ensure the smooth operation of external water supply networks.

The initial stage of installing external water supply networks

After the assignment for the design of the water supply system has been drawn up and all preliminary operations have been carried out, the construction of water supply networks begins at the planned site. The first step is excavation, which consists in digging trenches for the pipeline. Further, the bottom of the trenches is covered with quartz sand, which will ensure the safe location of the pipeline pipes. At the third stage, pipeline pipes are mounted.

The trench is dug from a water source 50 centimeters below the freezing depth. And when digging the trenches themselves, the slope of the external water supply should be taken into account, which should be no more than three centimeters per meter of the site.

There are several ways in which water supply and sewerage can be laid - ground and underground. Aboveground is carried out along flyovers and supports, and underground is trench and trenchless. The trench underground laying system may differ in the use of special equipment or be carried out manually. Trenchless underground laying is installed only with the help of HDD (horizontal directional drilling) installations. In cases where it is not possible to install a pipeline using a trench method, external networks are installed in some sections using GPN installations and the formation puncture method.

Therefore, in addition to the trench method, the trenchless method has recently been used, which includes the laying of cases. It is possible to identify the following advantages in trenchless laying: economically less expensive, more automated, low cost, safer for the environment. This type of laying is carried out by installing cases under the pipeline. In this case, the diameter of the water supply case must exceed the diameter of the pipes themselves.

The final stage of the installation of external water supply networks

Returning to the stages of installation of external networks, it should be noted that wells, shut-off and control valves, distribution columns, fire hydrants are further installed. It is important to note that quartz sand is used not only to create a foundation for placing pipes in trenches, but also to seal pipes in the future. For this, its layer-by-layer backfill is used. Thus, it is established that the external fire water supply, that all other external networks.

After the main external networks and water supply facilities are installed, the restoration work of the installation site takes place, which may be accompanied by the introduction of landscaping elements to the landscape area. Further acts of hidden works are already signed. And after connecting the external water supply networks to the plumbing systems of the premises, the final execution of all documentation of an executive and technical nature takes place.

Testing of external water supply networks

After the installation of external networks, the water supply system is always tested for strength and tightness in order to verify the quality of the work performed and the suitability of the water supply system for use. In this case, a preliminary test takes place before the installation of stop valves and backfilling of dug trenches. However, the final test is carried out only after completion of all work. So, the calculation of the water supply for strength is carried out by checking it with internal pressure. The test is considered to have been successfully completed when there is no rupture of the pipes, no damage or leakage at the butt joints.

Additional Information

Additionally, a few points need to be clarified. There is a frequently asked question “what should be the distance between the water supply and sewerage inlets”, in other words, between the input and output. As a rule, the water supply inlet is located either to the left or to the right of the sewer outlet. The distance between them should be more than one and a half meters with an input diameter of up to 200 mm, and more than three meters with a diameter of more than 200 mm.

Many in the private home sector have regularly encountered written notices of unauthorized water connections.

You should be aware that the fine for unauthorized connection to the water supply is more than 25 thousand rubles, and the violator is disconnected from the network.

To avoid this, it is recommended to use only legal connection methods. For an official connection to the water supply, it is required to agree on a project plan for external networks and obtain permissions from the relevant authorities, as described above.

There are also issues related to existing water supply schemes. Distribution is of several types. The main ones are ring and dead-end. The ring is characterized by uninterrupted water supply. With this wiring, much more consumables are required than when installing dead-end wiring. The latter supplies small businesses, and also turns on in case of accidents at the ring road.

In general, this is all you need to know about outdoor plumbing networks. In this article, you can get acquainted in detail not only with the existing features of installing external networks, but also get additional information on current issues. In the field of laying external water supply networks, the most interesting are new methods of trenchless laying. With their early introduction and mass application, it will be possible to install and repair a water supply system without blocking roads and increased cluttering of the surface.

Details 29.12.2011 13:00

Page 4 of 6

10.5. The level of the floor of machine rooms of buried pumping stations should be determined based on the installation of pumps of greater capacity or dimensions, taking into account 10.3.
In pumping stations of category III, it is allowed to install foot valves with a diameter of up to 200 mm on the suction pipeline.
10.6. The number of suction lines to the pumping station, regardless of the number and groups of installed pumps, including fire pumps, must be at least two.
When turning off one line, the rest should be designed to skip the full design flow for pumping stations of categories I and II and 70% of the design flow for category III.
The device of one suction line is allowed for category III pumping stations.
10.7. The number of pressure lines from pumping stations of categories I and II must be at least two. For category III pumping stations, one pressure line is allowed.
10.8. Piping and placement of shut-off valves on suction and pressure pipelines should provide the ability to:
water intake from any of the suction lines when any of them is turned off by each pump;
replacement or repair of any of the pumps, check valves and main shut-off valves, as well as checking the characteristics of the pumps without violating the requirements of 10.4 for the availability of water supply;
water supply to each of the pressure lines from each of the pumps when one of the suction lines is turned off.
10.9. The discharge line of each pump must be equipped with a shut-off valve and, as a rule, a check valve installed between the pump and the shut-off valve.
In the event of a possible occurrence of water hammer when the pump is stopped, check valves must be equipped with devices that prevent their rapid closing ("slamming").
When installing mounting inserts, they should be placed between the shut-off valve and the non-return valve.
On the suction lines of each pump, shut-off valves should be installed at pumps located under the bay or connected to a common suction manifold.
10.10. The diameter of pipes, fittings and fittings should be taken on the basis of a technical and economic calculation based on the speed of water movement within the limits indicated in table 24.

Pipe diameter, mm Velocity of water movement in pumping pipelines
stations, m/s
suction pressure
Up to 250 0.6 - 1 0.8 - 2
Over 250 to 800 0.8 - 1.5 1 - 3
St. 800 1.2 - 2 1.5 - 4

10.11. The dimensions of the machine room of the pumping station should be determined taking into account the requirements of section 13.
10.12. To reduce the dimensions of the station in terms of plan, it is allowed to install pumps with the right and left rotation of the shaft, while the impeller must rotate in only one direction.
10.13. Suction and pressure manifolds with shut-off valves should be located in the building of the pumping station.
10.14. Pipelines in pumping stations, as well as suction lines outside the machine room, as a rule, should be made of steel pipes, welded using flanges for connecting to valves and pumps.
In this case, it is necessary to provide for their fastening, which ensures the prevention of the pipes resting on the pumps and the mutual transmission of vibration from the pumps and pipeline units.
10.15. The design and dimensions of the receiving tanks of the stations should ensure the prevention of conditions for the formation of turbulence (turbulence) in the flow of the pumped liquid. This can be ensured by deepening the suction pipe by two of its diameters relative to the minimum liquid level, but by more than the required cavitation reserve set by the pump manufacturer, as well as by the distance from the suction pipe to the liquid inlet, to gratings, to sieves, etc. - at least five pipe diameters. For parallel operation of groups of pumps with a flow of each unit of more than 315 l / s, flow-directing walls between the pumps should be provided.
The diameter of the suction pipe is usually larger than the suction port of the pump. Transitions for horizontally located suction pipes should be eccentric with a straight top to avoid the formation of air fields in them. The suction pipeline must have a continuous rise to the pump of at least 0.005.
The distance from the suction pipe of the pump to the nearest fitting (outlet, armature, etc.) must be at least five pipe diameters.
10.16. In buried and semi-buried pumping stations, measures should be taken to prevent possible flooding of units in the event of an accident within the machine room at the largest pump in terms of productivity, as well as shut-off valves or pipelines by: location of pump motors at a height of at least 0.5 m from the machine room floor ; gravity release of an emergency amount of water into the sewer or onto the surface of the earth with the installation of a valve or gate valve, pumping water from the pit by the main pumps for industrial purposes.
If it is necessary to install emergency pumps, their performance should be determined from the condition of pumping water from the engine room with a layer of 0.5 m or more than 2 hours, and one standby unit should be provided.
Note. When installing submersible (hermetic) pumps in a "dry" design in the engine room, the condition for the foundation lifting height above the floor is not necessary.

10.17. Floors and channels in the engine room should be provided with a slope towards the prefabricated pit.
On foundations for pumps, bumpers, grooves and pipes for water drainage should be provided.
If gravity drainage of water from the pit is not possible, drainage pumps should be provided.
10.18. In buried pumping stations operating in automatic mode, with a machine room depth of 20 or more, as well as in pumping stations with permanent staff, with a depth of more than 15, a passenger elevator should be provided.
10.19. In the pumping station, regardless of the degree of its automation, a sanitary unit (toilet and sink), a room and a locker for storing the clothes of the operating personnel (on-duty repair team) should be provided.
When the pumping station is located at a distance of no more than 30 m from industrial buildings with sanitary facilities, it is allowed not to provide a sanitary unit.
In pumping stations above water wells, a sanitary unit should not be provided. For a pumping station located outside a settlement or facility, a cesspool is allowed.
10.20. In a separately located pumping station for minor repairs, a workbench should be provided.
10.21. In pumping stations with internal combustion engines, it is allowed to place consumable containers with liquid fuel (gasoline up to 250 l, diesel fuel 500 l) in rooms separated from the engine room by fireproof structures with a fire resistance limit of at least 2 hours.
10.22. In pumping stations, installation of control and measuring equipment should be provided in accordance with the instructions in section 14.

11. Water pipelines, water supply networks and structures on them

11.1. The number of water conduit lines should be taken taking into account the category of water supply of the water supply system and the sequence of construction.
11.2. When laying conduits in two or more lines, the need for a device for switching between them should be determined depending on the number of independent water intake structures or conduit lines supplying water to the consumer, while in the event that one conduit or its section is disconnected, the total water supply to the facility for household and drinking needs is allowed reduce by 30% of the estimated consumption, for production needs - according to the emergency schedule, for fire needs - in accordance with the requirements of the Fire Safety Regulations.
11.3. When laying a conduit in one line and supplying water from one source, the volume of water must be provided for the time of elimination of an accident on the conduit in accordance with 11.5. When water is supplied from several sources, the emergency volume of water can be reduced, provided that the requirements of 11.2 are met.
11.4. The estimated time to eliminate an accident on pipelines of water supply systems of category I should be taken according to table 25. For water supply systems of categories II and III, the time indicated in the table should be increased by 1.25 and 1.5 times, respectively.

Table 25

Estimated time of liquidation of accidents on pipelines
various diameters and laying

Pipe diameter, mm Estimated time to eliminate accidents on pipelines,
h, at pipe laying depth, m
up to 2 more than 2
Up to 400 8 12
Over 400 to 1000 12 18
St. 1000 18 24
Notes. 1. Depending on the material and diameter of the pipes,
features of the route of water conduits, conditions for laying pipes, availability of roads,
vehicles and means of liquidation of accidents, the specified time may
be changed, but must be taken for at least 6 hours.
2. It is allowed to increase the time of liquidation of the accident, provided that
the duration of interruptions in the supply of water and a decrease in its supply will not be
exceed the limits specified in 7.4.
3. If necessary, disinfection of pipelines after liquidation
accident, the time indicated in the table should be increased by 12 hours.
4. The time of liquidation of the accident, indicated in the table, includes the time
localization of the accident, i.e. disconnection of the emergency section from the rest
networks. For systems I, II, III categories, this time should not exceed,
respectively, 1 hour, 1.25 hours and 1.5 hours after the accident was detected.

11.5. Water networks should be ring. Dead-end water lines are allowed to be used:
for supplying water for production needs - if a break in water supply is permissible for the duration of the liquidation of the accident;
for supplying water for household and drinking needs - with a pipe diameter of not more than 100 mm;
for supplying water for fire-fighting or household fire-fighting needs, regardless of the water consumption for fire extinguishing - with a line length of not more than 200 m.
Ringing of external water supply networks with internal water supply networks of buildings and structures is not allowed.
Note. In settlements with a population of up to 5 thousand people. and water consumption for fire extinguishing up to 10 l / s or with the number of internal fire hydrants in the building up to 12, dead-end lines longer than 200 m are allowed, provided that fire-fighting tanks or reservoirs, a water tower or a counter-reservoir at the end of the dead end are installed.

11.6. When turning off one section (between settlement nodes), the total water supply for household and drinking needs along the remaining lines should be at least 70% of the estimated flow rate, and the water supply to the most unfavorably located water intake points should be at least 25% of the estimated water consumption, while free head should be at least 10 m.
11.7. The device of accompanying lines for connecting associated consumers is allowed with a diameter of main lines and water conduits of 800 mm or more and a transit flow of at least 80% of the total flow; for smaller diameters - upon justification.
With a width of passages of more than 20 m, it is allowed to lay duplicate lines, excluding the intersection of passages with inputs.
In these cases, the installation of fire hydrants should be carried out in accordance with paragraphs of SP 8.13130.
If the width of the streets within the red lines is 60 m or more, the option of laying water supply networks on both sides of the streets should also be considered.
11.8. The connection of networks of domestic drinking water supply systems with networks of water supply systems supplying water of non-potable quality is not allowed.
Note. In exceptional cases, in agreement with the bodies of the sanitary and epidemiological service, it is allowed to use a drinking water supply system as a reserve for a water supply system that supplies water of non-potable quality. The design of the jumper in these cases should provide an air gap between the networks and exclude the possibility of reverse water flow.

11.9. On water conduits and lines of the water supply network, if necessary, it is necessary to provide for the installation of:
rotary gates (latches) for allocation of repair sites;
valves for air inlet and outlet when emptying and filling pipelines;
valves for air inlet and pinching;
plungers for air release during pipeline operation;
compensators;
mounting inserts;
check valves or other types of automatic valves to include repair areas;
pressure regulators;
devices for preventing pressure increase in case of hydraulic shocks or in case of malfunction of pressure regulators.
On pipelines with a diameter of 800 mm or more, it is allowed to install unloading chambers or install equipment that protects water conduits under all possible operating modes from increasing pressure above the limit allowed for the accepted type of pipes.
Notes. 1. The use of gate valves instead of butterfly valves is allowed if it is necessary to systematically clean the inner surface of pipelines with special units.
2. Pipe fittings installed for operational purposes must be equipped with an electric drive with remote control.

11.10. The length of repair sections of conduits should be taken: when laying conduits in two or more lines and in the absence of switching - no more than 5 km; in the presence of switches - equal to the length of the sections between switches, but not more than 5 km; when laying water conduits in one line - no more than 3 km.
Note. The division of the water supply network into repair sections should ensure that when one of the sections is turned off, no more than five fire hydrants are turned off and water is supplied to consumers who do not allow a break in water supply.

With justification, the length of the repair sections of water conduits can be increased.
11.11. Automatic valves for air inlet and outlet should be provided at elevated breakpoints of the profile and at the upper boundary points of the repair sections of water conduits and networks to prevent the formation of a vacuum in the pipeline, the value of which exceeds the allowable value for the accepted type of pipes, as well as to remove air from the pipeline when it filling.
When the vacuum value does not exceed the allowable one, manually operated valves can be used.
Instead of automatic valves for air inlet and outlet, it is allowed to provide automatic valves for air inlet and pinching with valves (gates, gate valves) with a manual drive or air vents - depending on the flow rate of the removed air.
11.12. Plungers should be provided at elevated turning points of the profile on the air collectors. The diameter of the air collector should be taken equal to the diameter of the pipeline, the height is 200 - 500 mm, depending on the diameter of the pipeline.
When justified, it is allowed to use air collectors of other sizes.
The diameter of the shut-off valves that disconnect the air vent from the air collector should be taken equal to the diameter of the air vent connecting pipe.
The required capacity of the air vents should be determined by calculation or taken equal to 4% of the maximum design flow rate of water supplied through the pipeline, based on the volume of air at normal atmospheric pressure.
If there are several elevated turning points of the profile on the conduit, then at the second and subsequent points (counting in the direction of water movement), the required capacity of the plungers can be taken equal to 1% of the maximum design water flow, provided that this turning point is located below the first or above it by no more than 20 m and at a distance from the previous one no more than 1 km.
Note. When the slope of the descending section of the pipeline (after the turning point of the profile) is 0.005 or less, plungers are not provided; with a slope in the range of 0.005 - 0.01 at the turning point of the profile, instead of a plunger, it is allowed to provide a tap (valve) on the air collector.

11.13. Water conduits and water supply networks should be designed with a slope of at least 0.001 towards the outlet; with flat terrain, the slope can be reduced to 0.0005.
11.14. Releases should be provided at the low points of each repair site, as well as at the points of release of water from flushing pipelines.
The diameters of the outlets and the devices for air inlet should ensure the emptying of sections of water conduits or networks in no more than 2 hours.
The design of the outlets and the device for flushing pipelines should ensure the possibility of creating a water velocity in the pipeline of at least 1.1 maximum design.
Butterfly valves should be used as stop valves.
Note. During hydropneumatic flushing, the minimum speed of the mixture (in places of greatest pressure) must be at least 1.2 times the maximum speed of water, the water flow rate is 10-25% of the volumetric flow rate of the mixture.

11.15. Water drainage from outlets should be provided to the nearest drain, ditch, ravine, etc. If it is impossible to drain all or part of the discharged water by gravity, it is allowed to discharge water into the well with subsequent pumping.
11.16. Compensators should be provided:
on pipelines, the butt joints of which do not compensate for axial movements caused by changes in the temperature of water, air, soil;
on steel pipelines laid in tunnels, channels or on overpasses (supports);
on pipelines in conditions of possible soil subsidence.
The distances between compensators and fixed supports should be determined by a calculation that takes into account their design. When laying underground water conduits, mains and network lines from steel pipes with welded joints, expansion joints should be provided at the installation sites of cast-iron flange fittings. In cases where the cast-iron flanged reinforcement is protected from the effects of axial tensile forces by rigidly embedding steel pipes in the walls of the well, by installing special stops or by compressing the pipes with compacted soil, compensators may not be provided.
When compressing pipes with soil in front of flanged cast iron fittings, movable butt joints (elongated socket, coupling, etc.) should be used. Compensators and movable butt joints for underground laying of pipelines should be located in wells.
11.17. Mounting inserts should be taken for dismantling, routine inspection and repair of flanged shut-off, safety and control valves.
11.18. Shutoff valves on water conduits and lines of the water supply network must be manually or mechanically driven (from mobile vehicles).
The use of shut-off valves with an electric or hydropneumatic drive on water conduits is allowed with remote or automatic control.
11.19. The radius of action of the water intake column should be taken no more than 100 m. A blind area 1 m wide with a slope of 0.1 from the column should be provided around the water intake column.
11.20. The choice of material and strength class of pipes for water conduits and water supply networks should be made on the basis of a static calculation, the aggressiveness of the soil and transported water, as well as the operating conditions of pipelines and water quality requirements. For pressure conduits and networks, as a rule, non-metallic pipes (reinforced concrete pressure pipes, chrysotile cement pressure pipes, plastic pipes, etc.) should be used. Refusal to use non-metallic pipes must be justified. The use of cast-iron (including ductile iron) pressure pipes is allowed within settlements, territories of industrial enterprises, and in agricultural enterprises. The use of steel pipes is allowed: in areas with a design internal pressure of more than 1.5 MPa (15 kgf / cm2); for crossings under railways and roads, through water barriers and ravines; at the intersection of the utility and drinking water supply with sewerage networks; when laying pipelines along road and city bridges, along overpass supports and in tunnels. Steel pipes should be taken in economical grades with a wall thickness of which should be determined by calculation (but not less than 2 mm) taking into account the operating conditions of pipelines. For reinforced concrete and chrysotile cement pipelines, the use of metal fittings is allowed. The material of pipes in domestic and drinking water supply systems must meet the requirements of 4.4.
11.21. The value of the calculated internal pressure should be taken equal to the highest possible pressure in the pipeline in various sections along the length (in the most unfavorable operating mode) without taking into account the increase in pressure during hydraulic shock or with an increase in pressure during impact, taking into account the action of shockproof fittings, if this pressure is in combined with other loads (11.25) will have a greater effect on the pipeline.
Static analysis should be performed on the effect of the design internal pressure, soil pressure, live loads, the dead weight of the pipes and the mass of the transported liquid, atmospheric pressure during the formation of a vacuum and the external hydrostatic pressure of groundwater in those combinations that turn out to be the most dangerous for pipes of this material.
Pipelines or their sections should be divided according to the degree of responsibility into the following classes:
pipelines for objects of the I category of water supply security, as well as sections of pipelines in the zones of transition through water barriers and ravines, railways and roads of I and II categories and in places difficult to access to eliminate possible damage, for objects of II and III categories of water supply security;
pipelines for facilities of category II of water supply availability (with the exception of sections of class I), as well as sections of pipelines laid under improved road surfaces for facilities of category III of water supply security;
all other sections of pipelines for facilities of the III category of water supply security.
11.22. The magnitude of the test pressure at various test sections to which pipelines must be subjected before commissioning should be indicated in the construction organization projects, based on the strength characteristics of the material and class of pipes adopted for each section of the pipeline, the calculated internal water pressure and the magnitude of external loads acting on pipeline during the test period.
The calculated value of the test pressure should not exceed the following values for pipe pipelines:
cast iron - factory test pressure with a coefficient of 0.5;
reinforced concrete and chrysotile cement - hydrostatic pressure provided for by state standards or technical conditions for the corresponding classes of pipes in the absence of external load;
steel and plastic - internal design pressure with a coefficient of 1.25.
11.23. Cast iron, chrysotile cement, concrete, reinforced concrete pipelines must be designed for the combined effect of the calculated internal pressure and the calculated reduced external load.
Steel and plastic pipelines shall be designed for internal pressure in accordance with 11.22 and for the combined effect of external reduced load, atmospheric pressure, and also for the stability of the round shape of the pipe cross-section.
The shortening of the vertical diameter of steel pipes without internal protective coatings should not exceed 3%, and for steel pipes with internal protective coatings and plastic pipes, it should be taken according to the standards or specifications for these pipes.
When determining the vacuum value, the action of anti-vacuum devices provided on the pipeline should be taken into account.
11.24. As temporary loads should be taken:
for pipelines laid under railways - the load corresponding to the class of the given railway line;
for pipelines laid under roads - from a column of H-30 cars or wheeled vehicles NK-80 (for greater force on the pipeline);
for pipelines laid in places where traffic of motor vehicles is possible - from a column of H-18 cars or caterpillar NG-60 (for greater force impact on the pipeline);
for pipelines laid in places where the movement of road transport is impossible - a uniformly distributed load of 5 kPa (500 kgf / m2).
11.25. When calculating pipelines for pressure increase during hydraulic shock (determined taking into account shockproof fittings or vacuum formation), the external load should be taken no more than the load from the column of H-18 vehicles.
11.26. The increase in pressure during water hammer should be determined by calculation and, on its basis, protective measures should be taken.
Measures to protect water supply systems from water hammer should be provided for the following cases:
sudden shutdown of all or a group of pumps working together due to a power failure;
shutdown of one of the pumps working together before closing the butterfly valve (valve) on its pressure line;
starting the pump with an open butterfly valve (valve) on the pressure line equipped with a check valve;
mechanized closing of the rotary gate (valve) when the water conduit is turned off as a whole or its individual sections;
opening or closing quick-acting water fittings.
11.27. As measures to protect against water hammer caused by a sudden shutdown or start-up of pumps, the following should be taken:
installation of valves on the water conduit for air inlet and pinching;
installation of non-return valves with adjustable opening and closing on pressure lines of pumps;
installation of check valves on the conduit, dividing the conduit into separate sections with a small static pressure on each of them;
discharge of water through the pumps in the opposite direction with their free rotation or full braking;
installation at the beginning of the conduit (on the pressure line of the pump) of air-water chambers (caps) that soften the process of hydraulic shock.
Note. To protect against water hammer, it is allowed to use: installation of dampers, discharge of water from the pressure line to the suction line, water inlet in places of possible formation of breaks in the continuity of the flow in the water supply system, installation of blind diaphragms that collapse when the pressure rises above the permissible limit, installation of water columns, the use of pumping units with greater inertia of the rotating masses.

11.28. The protection of pipelines from the increase in pressure caused by the closing of the butterfly valve (valve) must be ensured by increasing the time of this closing. If the closing time of the gate with the accepted type of drive is insufficient, additional protection measures should be taken (installation of safety valves, air caps, water columns, etc.).
11.29. Water lines should generally be taken underground. During the heat engineering and feasibility study, ground and above-ground laying, laying in tunnels, as well as laying of water lines in tunnels together with other underground utilities, is allowed, with the exception of pipelines transporting flammable and combustible liquids and combustible gases.
When laying jointly in the passage channel, the domestic and drinking water supply should be laid above the sewer pipelines.
When laying underground, shut-off, control and safety valves should be installed in wells (chambers).
Wellless installation of shut-off valves is allowed upon justification.
11.30. The type of foundation for pipes must be taken depending on the bearing capacity of the soil and the magnitude of the loads.
In all soils, with the exception of rocky, peaty and silt, pipes should be laid on natural soil of an undisturbed structure, while ensuring leveling, and, if necessary, profiling the base.
For rocky soils, leveling of the base with a layer of sandy soil 10 cm thick above the ledges should be provided. It is allowed to use local soil (sandy loam and loam) for these purposes, provided it is compacted to a bulk density of the soil skeleton of 1.5 t/m3.
When laying pipelines in wet cohesive soils (loam, clay), the need for sand preparation is established by the project for the production of works, depending on the measures for dewatering, as well as on the type and design of pipes.
In silts, peaty and other weak water-saturated soils, pipes must be laid on an artificial base.
11.31. In cases where steel pipes are used, protection of their outer and inner surfaces from corrosion should be provided. In this case, the materials specified in 4.4 should be used.
11.32. The choice of methods for protecting the outer surface of steel pipes from corrosion should be justified by data on the corrosive properties of the soil, as well as data on the possibility of corrosion caused by stray currents.
11.33. In order to prevent corrosion and overgrowth of steel conduits and water supply networks with a diameter of 300 mm or more, protection of the inner surface of such pipelines with coatings: sand-cement, paintwork, zinc, etc.
Note. Instead of coatings, it is allowed to use stabilization treatment of water or its treatment with inhibitors in cases where technical and economic calculations, taking into account the quality, consumption and purpose of water, confirm the feasibility of such protection of pipelines from corrosion.

11.34. Corrosion protection of concrete of cement-sand coatings of pipes with a steel core from the effects of sulfate ions should be provided with insulating coatings.
11.35. For reinforced concrete pipes with a steel core, protection against corrosion caused by stray currents should be provided.
11.36. For reinforced concrete pipes with a steel core, having an outer layer of concrete with a density below normal, with an allowable crack opening width at design loads of 0.2 mm, it is necessary to provide for electrochemical protection of pipelines with cathodic polarization at a concentration of chloride ions in the soil of more than 150 mg/l; at normal concrete density and allowable crack width of 0.1 mm - more than 300 mg/l.
11.37. When designing pipelines from steel, cast iron and reinforced concrete pipes of all types, it is necessary to provide for measures to ensure continuous electrical conductivity of these pipes in order to be able to provide electrochemical protection against corrosion.
Note. When justified, it is allowed to install insulating flanges.

11.38. The cathodic polarization of pipes with a steel core should be designed so that the protective polarization potentials created on the metal surface, measured at specially arranged control and measuring points, are not lower than 0.85 V and not higher than 1.2 V using a copper sulfate reference electrode.
11.39. During electrochemical protection of pipes with a steel core using protectors, the value of the polarization potential should be determined with respect to a copper-sulfate reference electrode installed on the surface of the pipe, and when protected using cathode stations, with respect to a copper-sulfate reference electrode located in the ground.
11.40. The depth of the laid pipes, counting to the bottom, should be 0.5 m more than the calculated depth of penetration into the soil of zero temperature. When laying pipelines in the zone of negative temperatures, the material of pipes and elements of butt joints must meet the requirements of frost resistance.
Note. A smaller depth of laying of pipes is allowed to be taken, subject to the adoption of measures that exclude: freezing of fittings installed on the pipeline; unacceptable reduction in the throughput of the pipeline as a result of the formation of ice on the inner surface of the pipes; damage to pipes and their butt joints as a result of water freezing, soil deformation and thermal stresses in the pipe wall material; the formation of ice plugs in the pipeline during interruptions in the water supply associated with damage to the pipelines.

11.41. The estimated depth of penetration into the soil of zero temperature should be established on the basis of observations of the actual depth of freezing in the calculated cold and little snow winter and the experience of operating pipelines in this area, taking into account possible changes in the previously observed freezing depth as a result of planned changes in the state of the territory (removal of snow cover, arrangement improved road surfaces, etc.).
In the absence of observational data, the depth of zero temperature penetration into the soil and its possible change due to the proposed changes in the improvement of the territory should be determined by thermal engineering calculations.
11.42. To prevent heating of water in the summer, the depth of laying of pipelines of domestic and drinking water pipelines should, as a rule, be taken at least 0.5 m, counting to the top of the pipes. It is allowed to accept a smaller depth of laying water conduits or sections of the water supply network, subject to justification by thermal engineering calculations.
11.43. When determining the depth of laying of water conduits and water supply networks during underground laying, external loads from transport and the conditions of intersection with other underground structures and communications should be taken into account.
11.44. The choice of pipe diameters for water conduits and water supply networks should be made on the basis of technical and economic calculations, taking into account the conditions for their operation during emergency shutdown of individual sections.
The diameter of the pipes of the water supply, combined with the fire, is taken in accordance with SP 8.13130.
11.45. The value of the hydraulic slope to determine the pressure loss in pipelines during the transportation of water that does not have pronounced corrosive properties and does not contain suspended impurities, the deposition of which can lead to intensive overgrowth of pipes, should be taken on the basis of reference data.
11.46. For existing networks and water conduits, if necessary, measures should be taken to restore and maintain throughput by cleaning the inner surface of steel pipes and applying an anti-corrosion protective coating; in exceptional cases, upon agreement during the feasibility study, it is allowed to accept the actual pressure losses.
11.47. When designing new and reconstructing existing water supply systems, devices and devices should be provided for the systematic determination of the hydraulic resistance of pipelines in the control sections of water conduits and networks.
11.48. The location of the water supply lines on the master plans, as well as the minimum distances in the plan and at intersections from the outer surface of the pipes to structures and engineering networks should be taken in accordance with SP 18.13330 and SP 42.13330.
11.49. When laying several lines of water conduits in parallel (newly or in addition to existing ones), the distance in the plan between the outer surfaces of the pipes should be set taking into account the production and organization of work and the need to protect adjacent water conduits from damage in the event of an accident on one of them:
with an allowable reduction in the supply of water to consumers, provided for in 11.2 - according to table 26, depending on the material of the pipes, internal pressure and geological conditions;
if there is a spare tank at the end of the conduits, allowing interruptions in the water supply, the volume of which meets the requirements of 11.6 - according to table 26 as for pipes laid in rocky soils.

Table 26

Distances between pipes during laying
in soils of various types

Pipe material Diameter,
mm Type of soil (according to nomenclature SP 35.13330)

rocky soil
coarse-grained
rocks, sand
gravelly,
coarse sand,
clay sand medium
grains, sand
fine sand
dusty, sandy loam,
loams, soils
mixed with
vegetable
leftovers,
peated
soils
Pressure, MPa (kgf/cm2)
<= 1 (10) > 1 (10) <= 1 (10) > 1 (10) <= 1 (10) > 1 (10)
Distances in the plan between the outer surfaces of the pipes, m
Steel Up to 400 0.7 0.7 0.9 0.9 1.2 1.2
Steel St. 400
up to 1000 1 1 1.2 1.5 1.5 2
Steel St. 1000 1.5 1.5 1.7 2 2 2.5
Cast iron Up to 400 1.5 2 2 2.5 3 4
Cast iron St. 400 2 2.5 2.5 3 4 5
Reinforced concrete Up to 600 1 1 1.5 2 2 2.5
Reinforced concrete St. 600 1.5 1.5 2 2.5 2.5 3
Chrysotile
cement up to 500 1.5 2 2.5 3 4 5
Plastics Up to 600 1.2 1.2 1.4 1.7 1.7 2.2
Plastic St. 600 1.6 - 1.8 - 2.2 -

In certain sections of the route of water conduits, including in the areas of laying water conduits in a built-up area and on the territory of industrial enterprises, the distances given in Table 26 can be reduced if pipes are laid on an artificial foundation, in a tunnel, a case, or when using other laying methods that exclude the possibility damage to neighboring conduits in the event of an accident on one of them. At the same time, the distances between the conduits should ensure the possibility of performing work both during laying and during subsequent repairs.
11.50. When laying water lines in tunnels, the distance from the pipe wall to the inner surface of the enclosing structures and the walls of other pipelines should be taken at least 0.2 m; when installing fittings on the pipeline, the distances to the enclosing structures should be taken in accordance with 11.62.
11.51. Pipeline crossings under railways of categories I, II and III, the general network, as well as under roads of categories I and II should be accepted in cases, while, as a rule, a closed method of work should be provided. When justified, it is allowed to provide for the laying of pipelines in tunnels.
Under the rest of the railways and roads, it is allowed to arrange pipeline crossings without cases, while, as a rule, steel pipes and an open method of work should be used.
Notes. 1. Laying pipelines on railway bridges and overpasses, pedestrian bridges over tracks, in railway, road and pedestrian tunnels, as well as in culverts is not allowed.
2. Cases and tunnels under railways with an open method of work should be designed in accordance with SP 35.13330.
3. When justified, cases and water-bearing networks are allowed to be made of polymer pipes of increased strength.

11.52. The vertical distance from the bottom of the rail of a railway track or from the pavement of a highway to the top of a pipe, case or tunnel should be taken in accordance with SP 42.13330.
Deepening of pipelines at crossing points in the presence of heaving soils should be determined by thermal engineering calculation in order to exclude frost heaving of the soil.
11.53. The distance in plan from the edge of the case, and in the case of a device at the end of the well case - from the outer surface of the well wall should be taken:
when crossing railways - 8 m from the axis of the extreme track, 5 m from the bottom of the embankment, 3 m from the edge of the excavation and from the extreme drainage structures (cuvettes, upland ditches, flumes and drains);
when crossing motor roads - 3 m from the edge of the subgrade or the bottom of the embankment, the edge of the excavation, the outer edge of the upland ditch or other drainage structure.
The distance in plan from the outer surface of the case or tunnel should be taken at least:
3 m - to the supports of the contact network;
10 m - to switches, crosses and places where the suction cable is connected to the rails of electrified roads;
30 m - to bridges, culverts, tunnels and other artificial structures.
Note. The distance from the edge of the case (tunnel) should be specified depending on the availability of long-distance communication cables, signaling, etc., laid along the roads.

11.54. The inner diameter of the case should be taken in the production of works:
open method - 200 mm more than the outer diameter of the pipeline;
closed way - depending on the length of the transition and the diameter of the pipeline in accordance with SP 48.13330.
Note. It is allowed to lay several pipelines in one case or tunnel, as well as joint laying of pipelines and communications (electric cables, communications, etc.).

11.55. Pipeline crossings over railways must be provided in cases on special overpasses, taking into account the requirements of 11.53 and 11.57.
11.56. When crossing an electrified railway, measures must be taken to protect pipes from corrosion caused by stray currents.
11.57. When designing crossings over railways of categories I, II and III of the general network, as well as highways of categories I and II, measures should be taken to prevent undermining or flooding of roads in case of damage to pipelines.
At the same time, on the pipeline on both sides of the crossing under the railways, as a rule, wells should be provided with the installation of shutoff valves in them.
11.58. The project of crossing over railways and roads must be coordinated with the relevant authorities of railway and road transport.
11.59. When crossing pipelines through watercourses, the number of siphon lines must be at least two; when one line is turned off, the rest must be supplied with 100% of the calculated water flow. The siphon lines must be laid from steel pipes with reinforced anti-corrosion insulation, protected from mechanical damage.
The design of the siphon through navigable watercourses must be coordinated with the river fleet authorities.
The depth of laying the underwater part of the pipeline to the top of the pipe should be at least 0.5 m below the bottom of the watercourse, and within the fairway on navigable watercourses - at least 1 m. In this case, the possibility of erosion and reformation of the watercourse channel should be taken into account.
The clear distance between the siphon lines must be at least 1.5 m.
The slope of the ascending part of the siphon should be taken no more than 20 ° to the horizon.
On both sides of the siphon, it is necessary to provide for the installation of wells and switches with the installation of shut-off valves.
The layout mark at the siphon wells should be taken 0.5 m above the maximum water level in the watercourse with a security of 5%.
Note. When justifying, the use of pipes made of other materials (plastic, etc.) is allowed.

11.60. At turns in the horizontal or vertical plane of pipelines from socket pipes or connected by couplings, when the resulting forces cannot be absorbed by the pipe joints, stops should be provided.
On welded pipelines, stops should be provided when the turns are located in wells or the angle of rotation in the vertical plane of the bulge is upwards of 30 ° or more.
Note. On pipelines made of socket pipes or connected by couplings with a working pressure of up to 1 MPa (10 kgf / cm2), at angles of rotation up to 10 °, it is allowed not to provide stops.

11.61. When determining the dimensions of wells, the minimum distances to the internal surfaces of the well should be taken:
from the walls of pipes with a pipe diameter of up to 400 mm - 0.3 m, from 500 to 600 mm - 0.5 m, more than 600 mm - 0.7 m;
from the plane of the flange with a pipe diameter of up to 400 mm - 0.3 m, more than 400 mm - 0.5 m;
from the edge of the socket facing the wall, with a pipe diameter of up to 300 mm - 0.4 m, more than 300 mm - 0.5 m;
from the bottom of the pipe to the bottom with a pipe diameter of up to 400 mm - 0.25 m, from 500 to 600 mm - 0.3 m, more than 600 mm - 0.35 m;
from the top of the stem of the valve with a rising stem - 0.3 m, from the handwheel of the valve with a non-rising stem - 0.5 m.
The height of the working part of the wells must be at least 1.5 m.
When placing a fire hydrant in a well, it should be possible to install a fire column in it.
11.62. In cases of installation of air inlet valves located in wells on water conduits, it is necessary to provide for a ventilation pipe, which, in the case of drinking water supply through water conduits, must be equipped with a filter.
11.63. For descending into the well on the neck and walls of the well, it is necessary to provide for the installation of corrugated steel or cast-iron brackets, the use of portable metal ladders is allowed.
For maintenance of fittings in wells, if necessary, platforms should be provided in accordance with 13.7.
11.64. In wells (when justified), it is necessary to provide for the installation of second insulating covers; if necessary, hatches with locking devices should be provided.

12. Water storage tanks

12.1. Reservoirs in water supply systems, depending on the purpose, should include control, fire, emergency and contact volumes of water.
12.2. The placement of reservoirs over the territory of water supply, their altitude location in volumes should be determined when developing the scheme and water supply system based on the results of hydraulic and optimization calculations included in the system of structures and devices, performed in accordance with the requirements set forth in 7.9, and also taking into account the provisions of the SP 8.13130.
As tanks, it is allowed to use underground, ground and above-ground tanks, tanks of water towers, as well as tanks located on the roofs of buildings, attics and intermediate technical floors.
Reservoirs (tanks), in which only emergency stock is stored, may be located at elevations at which water from the reservoir can enter the network only when the normal free pressure in the network decreases to emergency. Such reservoirs or tanks must be equipped with overflow devices in case of failure of the check valve separating the reservoir (tank) from the network.
In the tank at water treatment stations, an additional amount of water for filter washing should be taken into account.
Note. When justified in the reservoir, it is allowed to provide for the volume of water to regulate not only the hourly, but the daily unevenness of water consumption.

12.3. When water is supplied through one conduit in tanks, the following should be provided:
emergency volume of water, ensuring during the time of elimination of an accident on the water main (11.4) water consumption for household and drinking needs in the amount of 70% of the estimated average hourly water consumption and production needs according to the emergency schedule;
additional volume of water for fire extinguishing in the amount determined in accordance with SP 8.13130.
Notes. 1. The time required to restore the emergency volume of water should be taken as 36 - 48 hours.
2. Restoration of the emergency volume of water should be provided by reducing water consumption or using standby pumping units.
3. An additional volume of water for fire extinguishing is accepted in accordance with SP 8.13130.

12.4. The volume of water in tanks in front of pumping stations operating evenly should be taken at the rate of 5 - 10-minute performance of a pump with a higher capacity.
12.5. The contact volume of water to provide the required contact time of water with reagents should be determined in accordance with 9.127. The contact volume may be reduced by the value of the fire and emergency volumes, if any.
12.6. Tanks and their equipment must be protected from water freezing.
12.7. In drinking water tanks, the exchange of fire and emergency water volumes must be ensured within a period of not more than 48 hours.
Note. When justified, the period of water exchange in the tanks can be increased to 3-4 days. At the same time, it is necessary to provide for the installation of circulation pumps, the performance of which should be determined from the condition of replacing water in tanks within a period of not more than 48 hours, taking into account the flow of water from a water supply source.

Tank equipment

12.8. Water tanks and tanks of water towers must be equipped with: supply and discharge pipelines or a combined supply and discharge pipeline, an overflow device, a drain pipeline, a ventilation device, brackets or ladders, manholes for the passage of people and transportation of equipment.
Depending on the purpose of the tank, additionally it should be provided:
devices for measuring water level, vacuum and pressure control;
skylights with a diameter of 300 mm (in non-potable water tanks);
flushing water supply (portable or stationary);
a device to prevent water overflow from the tank (automatic means or installation of a float shut-off valve on the supply pipeline);
a device for cleaning the air entering the tank (in drinking water tanks).
12.9. At the end of the supply pipeline in reservoirs and tanks of water towers, a diffuser with a horizontal edge or a chamber should be provided, the top of which should be located 50 - 100 mm above the maximum water level in the tank.
12.10. A confuser should be provided on the outlet pipeline in the tank; with a pipeline diameter of up to 200 mm, it is allowed to use a receiving valve located in the pit (see 10.5).
The distance from the edge of the confuser to the bottom and walls of the tank or pit should be determined on the basis of the speed of water approaching the confuser no more than the speed of water movement in the inlet section.
The horizontal edge of the confuser, arranged in the bottom of the tank, as well as the top of the pit, should be 50 mm higher than the concrete bottom. A grate must be provided on the discharge pipeline or pit. Outside the reservoir or water tower, on the outlet (supply-outlet) pipeline, a device should be provided for water sampling by tank trucks and fire engines.
12.11. The overflow device must be designed for a flow rate equal to the difference between the maximum supply and the minimum water withdrawal. The water layer on the edge of the overflow device should be no more than 100 mm.
In tanks and water towers intended for drinking water, a hydraulic seal must be provided on the overflow device.
12.12. The drain pipeline should be designed with a diameter of 100 - 150 mm, depending on the volume of the tank. The bottom of the tank must have a slope of at least 0.005 towards the downcomer.
12.13. Drain and overflow pipelines should be connected (without flooding their ends):
from water tanks of non-potable quality - to sewers of any purpose with a jet break or to an open ditch;
from potable water tanks to rainwater or an open ditch with a break in the flow.
When connecting an overflow pipeline to an open ditch, it is necessary to provide for the installation of gratings with 10 mm gaps at the end of the pipeline.
If it is impossible or inexpedient to discharge water through the discharge pipeline by gravity, a well should be provided for pumping water with mobile pumps.
12.14. Air inlet and outlet when the position of the water level in the tank changes, as well as air exchange in the tanks for storing fire and emergency volumes should be provided through ventilation devices that exclude the possibility of a vacuum exceeding 80 mm of water. Art.
In tanks, the air space above the maximum level to the lower edge of the slab or floor plane should be taken from 200 to 300 mm. The crossbars and supports of the slabs can be flooded, while it is necessary to ensure air exchange between all sections of the coating.
12.15. Manhole hatches should be located near the ends of the inlet, outlet and overflow pipelines. Manhole covers in potable water tanks must have locking and sealing devices. Tank hatches should rise above the floor insulation to a height of at least 0.2 m.
In potable water tanks, all hatches must be completely sealed.
12.16. The total number of tanks of the same purpose in one node must be at least two.
In all tanks in the node, the lowest and highest levels of fire, emergency and control volumes must be respectively at the same level.
When one tank is turned off, the rest must store at least 50% of the fire and emergency volumes of water.
Tank equipment should provide the possibility of independent switching on and emptying of each tank.
The device of one tank is allowed in the absence of fire and emergency volumes in it.
12.17. The design of the valve chambers at the tanks should not be rigidly connected with the design of the tanks.
12.18. Water towers can be designed with a tent around the tank or without a tent, depending on the mode of operation of the tower, the volume of the tank, climatic conditions and the temperature of the water in the water supply source.
Note. Water level sensors used to control the operation of pumps supplying water to the tower must be heated to prevent water overflow in winter.

12.19. The trunk of the water tower may be used to accommodate industrial premises of the water supply system, excluding the formation of dust, smoke and gas emissions.
12.20. In case of rigid sealing of pipes in the bottom of the tank of the water tower, compensators should be provided on the risers of the pipelines.
12.21. A water tower that is not included in the lightning protection zone of other structures must be equipped with its own lightning protection.
12.22. The volume of fire tanks and reservoirs should be determined based on the estimated water consumption and the duration of fire extinguishing in accordance with SP 8.13130.

13. Placement of equipment, fittings and pipelines

13.1. The instructions of the section should be taken into account when determining the dimensions of the premises, installing technological and handling equipment, fittings, as well as laying pipelines in buildings and water supply facilities.
13.2. When determining the area of industrial premises, the width of the aisles should be taken at least:
between pumps or electric motors - 1 m;
between pumps or electric motors and a wall in recessed rooms - 0.7 m, in others - 1 m; at the same time, the width of the passage on the side of the electric motor must be sufficient for dismantling the rotor;
between compressors or blowers - 1.5 m, between them and the wall - 1 m;
between fixed protruding parts of the equipment - 0.7 m;
in front of the electrical switchboard - 2 m.
Notes. 1. Passages around the equipment, regulated by the manufacturer, should be taken according to passport data.
2. For units with a discharge pipe diameter of up to 100 mm inclusive, it is allowed: installation of units against a wall or on brackets; installation of two units on the same foundation with a distance between the protruding parts of the units of at least 0.25 m, providing passages around the double installation with a width of at least 0.7 m.

13.3. For the operation of process equipment, fittings and pipelines in the premises, hoisting and transport equipment should be provided, while, as a rule, it should be taken: with a load weight of up to 5 tons - a manual hoist or a manual overhead crane beam; with a cargo weight of more than 5 tons - manual overhead crane; when lifting a load to a height of more than 6 m or with a crane runway length of more than 18 m - electric crane equipment.
Notes. 1. The use of inventory devices and installations is allowed.
2. It is not required to provide lifting cranes that are necessary only for the installation of process equipment (pressure filters, hydraulic mixers, etc.).
3. To move equipment and fittings weighing up to 0.3 tons, the use of rigging means is allowed.

13.4. In rooms with crane equipment, an installation site should be provided.
Delivery of equipment and fittings to the installation site should be carried out by rigging or hoist on a monorail leaving the building, and in justified cases - by vehicles.
Around the equipment or vehicle installed on the installation site in the service area of crane equipment, a passage with a width of at least 0.7 m must be provided.
The dimensions of gates or doors should be determined based on the dimensions of the equipment or the vehicle with the load.
13.5. The lifting capacity of crane equipment should be determined based on the maximum mass of the transported cargo or equipment, taking into account the requirements of equipment manufacturers for the conditions of its transportation.
In the absence of manufacturers' requirements for the transportation of equipment only in assembled form, the lifting capacity of the crane can be determined based on the part or part of the equipment with the maximum mass.
Note. Consideration should be given to the increase in the weight and dimensions of the equipment in cases where it is intended to be replaced by a more powerful one.

In front of openings and gates from the outside, it is necessary to provide appropriate areas for turning vehicles and lifting equipment.
13.6. Determination of the height of the premises (from the level of the installation site to the bottom of the floor beams) with handling equipment, and the installation of cranes should be carried out in accordance with GOST 7890.
In the absence of handling equipment, the height of the premises should be taken in accordance with SP 56.13330.
13.7. If the height to the places of maintenance and control of equipment, electric drives and flywheels of valves (gates) is more than 1.4 m from the floor, platforms or bridges should be provided, while the height to the places of maintenance and control from the platform or bridge should not exceed 1 m.
It is allowed to provide for the expansion of equipment foundations.
13.8. Installation of equipment and fittings under the installation site or service platforms is allowed at a height from the floor (or bridge) to the bottom of the protruding structures of at least 1.8 m. In this case, a removable covering of the platforms or openings should be provided above the equipment and fittings.
13.9. Gate valves (gates) on pipelines of any diameter with remote or automatic control must be electrically driven. It is allowed to use pneumatic, hydraulic or electromagnetic drives.
In the absence of remote or automatic control, shut-off valves with a diameter of 400 mm or less should be provided with a manual drive, with a diameter of more than 400 mm - with an electric or hydraulic drive; in some cases, when justified, it is allowed to install valves with a diameter of more than 400 mm with a manual drive.
13.10. Pipelines in buildings and structures, as a rule, should be laid above the floor surface (on supports or brackets) with the installation of bridges over the pipelines and ensuring the approach and maintenance of equipment and fittings.
It is allowed to lay pipelines in channels blocked by removable plates, or in basements.
The dimensions of the pipeline channels should be taken:
with a pipe diameter of up to 400 mm - the width is 600 mm, the depth is 400 mm more than the diameter;
with a pipe diameter of 500 mm and above - the width is 800 mm, the depth is 600 mm more than the diameter.
In places where flange fittings are installed, the channel should be widened. The slope of the bottom of the channels to the pit should be taken at least 0.005.

14. Electrical equipment, technological control,
automation and control systems

General instructions

14.1. The reliability categories of power supply of power receivers of water supply systems should be determined by.
The reliability category of the power supply of the pumping station must be the same as the category of the pumping station adopted according to 10.1.
14.2. The choice of voltage of electric motors should be made depending on their power, the adopted power supply scheme and taking into account the prospects for the development of the designed object; the choice of execution of electric motors - depending on the environment and the characteristics of the room in which the electrical equipment is installed.
14.3. Reactive power compensation should be carried out taking into account the requirements of the power supply organization and the feasibility study for the choice of installation sites for compensating devices, their power and voltage.
14.4. Distribution devices, transformer substations and control panels should be placed in built-in or attached premises, taking into account their possible expansion and increase in power. It is allowed to provide separate closed switchgears and transformer substations.
It is allowed to install closed shields in industrial premises and in fire pumping stations on the floor or balconies, with measures taken to prevent water from entering them.
14.5. When determining the volume of automation of water supply facilities, their productivity, mode of operation, degree of responsibility, reliability requirements, as well as the prospect of reducing the number of maintenance personnel, improving working conditions for workers, reducing electricity consumption, water and reagent consumption, environmental protection requirements are taken into account.
14.6. The automation system for water supply facilities should include:
automatic control of the main technological processes in accordance with a given mode or according to a given program;
automatic control of the main parameters characterizing the mode of operation of technological equipment and its condition;
automatic regulation of parameters that determine the technological mode of operation of individual structures and their efficiency.
14.7. To automate structures with a large number of control objects or technological operations over 25, it is advisable to use microprocessor controllers instead of relay-contact equipment.
14.8. The automatic control system should provide for the possibility of local control of individual devices or structures.
14.9. In technological control systems, it is necessary to provide: means and devices for automatic (continuous) control, means for periodic control (for adjusting and checking the operation of structures, etc.).
14.10. Technological control of water quality parameters should be carried out continuously by automatic instruments and analyzers or, in the absence of such, by laboratory methods.

Water intake facilities for surface and ground water

14.11. At the groundwater intake facilities with variable water consumption, it is recommended to provide for the following methods of pump control:
remote or telemechanical - according to the commands of their control point (CP);
automatic - depending on the water level in the receiving tank or on the pressure in the network.
14.12. For wells (shaft wells), automatic shutdown of the pump should be provided when the water level drops below the permissible level.
14.13. At water intake facilities for surface waters, it is necessary to provide for the control of level differences on gratings and grids, as well as for measuring the water level in chambers, in a reservoir or watercourse.
14.14. Groundwater intake facilities should provide for measuring the flow or amount of water supplied from each well (shaft well), the water level in the chambers, in the collection tank, as well as the pressure at the pressure nozzles of the pumps.

Pumping stations

14.15. Pumping stations for all purposes should be designed, as a rule, with control without permanent maintenance personnel:
automatic - depending on technological parameters (water level in tanks, pressure or water flow in the network);
remote (telemechanical) - from the control point;
local - periodically arriving personnel with the transfer of the necessary signals to the control point or point with the constant presence of service personnel.
14.16. For pumping stations with a variable mode of operation, it should be possible to regulate the pressure and flow of water, ensuring a minimum consumption of electricity. The regulation can be carried out stepwise - by changing the number of operating pumping units or smoothly - by changing the speed of the pumps, the degree of opening of the control valves and other methods, as well as a combination of these methods.
The choice of a method for regulating the operating mode of a pumping unit should be justified by technical and economic calculations.
14.17. The choice of the number of adjustable units and their parameters should be made on the basis of hydraulic and optimization calculations performed in accordance with the instructions in section 8.
As a controlled electric drive in pumping units, the following can be used: a frequency drive, a drive based on a brushless motor, and others.
The choice of the type of drive is carried out taking into account the design features of the pumping units, their power and voltage, as well as the predicted mode of operation of the pumping station.
14.18. In automated pumping stations, in case of emergency shutdown of working pumping units, the backup unit should be automatically switched on.
In telemechanized pumping stations, automatic switching on of the backup unit should be carried out for category I pumping stations.
14.19. In pumping stations of category I, self-starting of pumping units or their automatic switching on at intervals of time should be provided if simultaneous self-starting is impossible due to power supply conditions.
14.20. When a vacuum boiler is installed in the pumping station for filling the pumps, automatic operation of the vacuum pumps must be ensured depending on the water level in the boiler.
14.21. The automated control of each of the pumping stations included in the water supply and distribution system should be built taking into account its interaction with other pumping stations of the system (including system-wide and local pumping stations), as well as with control tanks and control devices on water conduits and networks. At the same time, the change in the water supply of unregulated pumps (as a result of their self-regulation) must be controlled so that they do not go beyond the allowable range of each of the pumps. In necessary cases, it is necessary to limit the unacceptable increase in flow by throttling, and its unacceptable decrease - by recirculation. Automated control of the operation of systems as a whole should ensure the supply of the required daily water flow at the minimum total power consumption by all pumps operating together, ensuring free pressure in the network is not lower than required and reducing to the possible minimum excess free pressure, causing an increase in water losses due to leaks and irrational consumption .
The system should provide water supply with the lowest possible energy costs per unit of supplied volume of water, preventing overloading of individual units, their operation in the zone of low efficiency, in the zones of surging and cavitation.
14.22. In pumping stations, blocking should be provided, which excludes the possibility of supplying an untouchable firefighter, as well as emergency volumes of water in tanks for other purposes.
14.23. Vacuum pumps in pumping stations with siphon water intake should operate automatically according to the water level in the air cap installed on the siphon line.
14.24. Pumping stations should provide for automation of the following auxiliary processes: washing of rotating screens according to a given program, adjustable in time or level difference, pumping out drainage water in the pit, sanitary systems, etc.
14.25. Pumping stations should provide for measuring pressure in pressure conduits, as well as monitoring the water level in the drainage pit and vacuum boiler, the temperature of the bearings of the units (if necessary), the emergency flood water level (the appearance of water in the machine room at the level of the foundations of electric drives).

Water treatment stations

14.26. Automation should be considered:
dosing of coagulants and other reagents;
the process of disinfection with chlorine, ozone and chlorine reagents, UV irradiation;
the process of fluorination and defluorination by the reagent method.
At variable water flow rates, automation of dosing of reagent solutions should be provided for by the ratio of the flow rates of the treated water and the reagent of constant concentration with local or remote correction of this ratio, if justified, by the quality indicators of the source water and reagents.
14.27. On filters and contact clarifiers, it is necessary to provide for the regulation of the filtration rate according to the water flow or the water level on the filters, ensuring a uniform distribution of water between them.
As a throttling device in filtration speed controllers, it is recommended to use butterfly valves and butterfly valves. The use of simple float valves is allowed. In cases where the filtration rate needs to be changed, controlled filtration rate regulators are used, which allow you to set the filter operation mode remotely from the control panel.
14.28. The withdrawal of filters for washing should be provided for by the water level, the magnitude of the pressure loss in the filter load or the quality of the filtrate; output for washing of contact clarifiers - by the magnitude of the pressure loss or decrease in flow rate with fully open control valves.
Filters and contact clarifiers are allowed to be washed out according to the time program.
14.29. At water treatment plants with more than 10 filters, the washing process should be automated. With the number of filters up to 10, semi-automatic interlocked flushing control from consoles or panels should also be provided.
14.30. The scheme for automating the process of washing filters and contact clarifiers should ensure the following operations are performed in a certain sequence:
control according to a given program of gates and valves on pipelines supplying and discharging treated water;
start and stop of wash water pumps and blowers during water-air washing.
14.31. The automation scheme should provide for an interlock that, as a rule, allows only one filter to be flushed at a time.
14.32. When flushing water is supplied by pumps, before washing the filters, it is recommended to provide for automatic air venting from the flushing water pipeline.
14.33. The duration of flushing should be set according to the time or the turbidity of the flushing water in the outlet pipe.
14.34. Washing of drum screens and microfilters should be carried out automatically according to a given program or according to the magnitude of the difference in water levels.
14.35. Pumps pumping reagent solutions must be locally controlled with automatic shutdown at specified levels of solutions in the tanks.
14.36. At installations for chemical softening of water, dosing of reagents according to pH and electrical conductivity should be automated. At installations for the removal of carbonate hardness and recarbonization of water, it is necessary to automate the dosing of reagents (lime, salt, etc.) by pH value, electrical conductivity, etc.
14.37. Regeneration of ion exchange filters should be automated:
cationic - according to the residual hardness of the water;
anionite - according to the electrical conductivity of the treated water.
14.38. Water treatment plants should control:
water consumption (original, treated, flushing and reused);
levels in filters, mixers, reagent tanks and other containers;
sludge levels in settling tanks and clarifiers, water flow and head loss;
in filters (if necessary) the value of residual chlorine or ozone;
the pH value of the source and treated water;
concentrations of reagent solutions (it is allowed to measure with portable devices and laboratory method);
other technological parameters that require operational control and are provided with appropriate technical means.