Spring check valve. Safety Spring Valves - All about the device and installation Features of the lever valve valves

Check valve is an element of a pipeline system, which provides for the movement of the working medium in only one direction. Its use is required for autonomous pumping stations and other equipment that can fail when the fluid flow moves in the opposite direction.

Reverse spring valve is one of the varieties of locking elements. It refers to the category of fittings direct action And it works automatically on the energy of the working medium, which warns the output of the equipment in order when the power supply is disabled and other faults.

Constructive features

The spring valve constructively consists of three elements:

The housing is usually made of brass and equipped with elements for fastening to the pipeline (coupling, thread). The housing is also made of steel, cast iron and polypropylene. The selection of the material is determined by the parameters of the working medium, the diameter of the pipeline.
The working element representing the movable spool includes two plates with a special hermetic gasket between them and the rod.
The executive body representing the spring located between the plates of the working element and the saddle. Provides automatic overlap of fluid current when a pressure decreases or a change in its direction. The minimum pressure of the working medium depends on the spring rigidity, at which the valve automatically opens.

Advantages of sprocket check valves:

the possibility of mounting in any position;
simplicity of design;
universality.

At the same time, the valve is sensitive to pollution in water, which lead to wear of sealing plates, so it is desirable to install a filter before it. It is also recommended to mount the valve in easily accessible places to simplify its maintenance and replacement.

It is desirable to install the valve in a vertical position so that the blocking force of the spring coincides with the action of gravity. For right mounting It is necessary to navigate the arrow applied to the valve body, which shows the transmitted direction of the current of the working medium.

Scope of application

Reverse Spring Valves are widely used in systems. autonomous water supply, Outdoor networks of apartment buildings. They are installed on the suction lines of pumps, in front of capacitive water heaters, boilers, water meters and other equipment.

An obligatory element of equipping autonomous water supply systems in dachas and in country houses is an check valve. That is technical devicewhich may have a different design version, ensures the movement of fluid on the pipeline in the desired direction. Check valves installed in the autonomous water supply system securely protect it from the effects of abnormal situations. Right-acting reinforcement devices, check valves work automatically, for which the energy of the working medium is used to be transported along the pipeline system.

Appointment and principle of operation

The main function that the return valve for water is performed is that it protects the water supply system from the critical fluid flow parameters transported through the pipeline. Most frequent cause Critical situations is to stop pumping installationIt can lead to a variety of negative phenomena - a plum of water from the pipeline back into the well, spinning the impeller of the pump in the opposite direction and, accordingly, breakage.

Protect the water supply system from listed negative phenomena allows the installation of the return valve to water. In addition, the return valve for water prevents the consequences that cause a hydraulic blow. The use of check valves in pipeline systems allows you to make their work more efficient, as well as ensure correct operation pumping equipmentwhich such systems are equipped.

The principle of operation of the check valve is quite simple and is as follows.

The flow of water coming into such a device under defined pressure, acts on the shut-off element and presses the spring, with which this item is held in the closed state.
After squeezing the spring and the opening of the shut-off element, the water begins to move freely through the check valve in the desired direction.
If the level of pressure level of the fluid in the pipeline drops or water begins to move not in the direction, the spring mechanism of the valve returns a shut-off element into a closed state.

Acting in this way, the reverse valve prevents the formation of an undesirable reverse stream in the pipeline system.

When choosing a shutter model installed on a water supply, it is important to know regulatory requirementsthat make the pumping equipment manufacturers to such devices. The technical parameters for which in accordance with these requirements choose the return valve for water, are:

working, trial and nominal closure pressure;
planting diameter;
conditional bandwidth;
sealing class.

Information about how technical requirements There must be a check valve for water, as a rule, contains in the documentation for pumping equipment.

To equip the water supply systems of the domestic purpose, sprocket-type check valves are used, the diameter of the conditional passage is 15-50 mm in the interval. Despite its compact sizes, such devices demonstrate high bandwidth, ensure the reliability of the pipeline operation, low noise and vibration in the pipeline system on which they are installed.

Another one positive factor The use of check valves in the water supply system is that they contribute to a decrease in pressure generated by a water pump, by a value of 0.25-0.5 atm. In this regard, the return valve for water allows you to reduce the load as on separate elements Equipping pipelines and the entire water supply system as a whole.

Constructive features

One of the most common materials from which the campaign of the water reverse valves make is brass. The selection of this material is not accidental: this alloy demonstrates extremely high resistance to the effects of chemically aggressive substances that can be in the water transported through the pipeline in a dissolved or weighted state. These substances, in particular, include mineral salts, sulfur, oxygen, manganese, iron compounds, etc. The outer surface of the shutters, which in the process of their operation is also exposed to negative factors, often protect special coating, applied galvanic method.

The reverse valve device assumes the presence of an spool for the manufacture of which brass or durable plastic can also be used. The sealing gasket present in the design of the check valve may be rubber or silicone. For the manufacture of an important element of the shut-off mechanism - the springs - use, as a rule, stainless steel.

So, if we talk about the structural elements of the spring check valve, then this device comprises:

compound type housings, whose elements are connected by means of thread;
shut-off mechanism, the design of which includes two movable spool plates installed on a special stock, and sealing gasket;
springs installed between spool plates and planting saddle at the outlet of the bandwidth.

The principle of operation of the spring check valve is also quite simple.

The flow of water flowing into the reverse shutter under the required pressure affects the spool and presses the spring.
When compressing the spring, the spool moves around the rod, opening the bandwidth and providing fluid stream the ability to move freely through the device.
When the water flow pressure falls in the pipeline on which the check valve is worth, or in cases where such a stream begins to move not in the direction, the spring returns a spool on it planting placeClosing the bandwidth of the device.

Thus, the scheme of the check valve is quite simple, but nevertheless provides high reliability of such devices and the effectiveness of their use in pipeline systems.

Main species

Recommending how the check valve is running, installed in watering system, It should also be understood how to choose it correctly. In the modern market are offered different kinds Reverse valve devices, design, manufacturing material and a work diagram of which can be seriously different.

Spring feed valve coupling type

The hull of the valves of this type consists of two cylindrical elements connected with a thread. The locking mechanism includes plastic rod, upper and lower spool plates. The position of the elements of the shut-off mechanism in the closed state, as well as their opening at the moment when the water flow pressure reaches the required level, provides a spring. Between themselves composite elements The housings are connected using the sealing gasket.

Spring check valve with brass spool and spherical shape spool

Distinctive features of the valves of this type are easy to notice even in the photo. The brass housing of such a valve in its middle part, where the spool camera is located, has a spherical shape. Such. constructive feature Allows you to increase the volume of the spool chamber and, accordingly, the bandwidth of the check valve. The shut-off mechanism of the water valve of this type, the basis of which is the brass spool, works on the same principle as in valve devices of any other type.

Combined check valve spring type with drainage and air vent

Many of those who decided to independently do the installation of the pipeline system, often the question of what the check valve is needed, equipped with drainage and air ventilation systems. The use of check valves of this type (especially for equipping pipelines for which hot workers are transported) allows you to simplify the installation and maintenance process of such systems, increase their reliability, reduce the total hydraulic pressure, reduce the number of mounting connections.

On the housing of the shutters of this type, which can be seen even in the photo, there are two nozzles, one of which is used for mounting the air vent, and the second performs the function of the drainage element. The nozzle for the air vent, on the inner surface of which the thread is sliced, is located on the device body above the spool chamber (its reception part). Such a pipe is needed for airbagging from the pipeline system, which is additionally used by Maevsky's crane. The purpose of the nozzle, which is located on the opposite side of the case - at the exit from the valve, is to merge the liquid from the system accumulated after the valve device.

If you set a horizontal check valve, then its air removal pipe can be used to mount a pressure gauge. If you put the combined check valve on the pipeline vertically, then its drainage nozzle can be used to drain the water accumulated after such a device, and the air supply pipe is for removal from that part of the pipeline, which is located before the check valve, aerial traffic. That is why, solving how to install a combined type check valve, you should clearly understand which functions should be performed.

Spring valves with polypropylene case

Check valves, the housing of which is made of polypropylene, even if you look at the photo of such devices, externally resemble oblique taps. Types of check valves, for the installation of which the polyfusion welding method is used, are installed on pipelines, also made of polypropylene. Additional oblique discharge in the design of the valves of this type is necessary to accommodate in it the elements of the locking mechanism, which facilitates maintenance Such a device. Thereby constructive decision Perform maintenance and repair of the check valve of this type is easy - it suffices to remove the elements of the locking mechanism from its additional removal, without violating the integrity of the body of the device and the tightness of its installation in the pipeline system.

Check valves of other types

Other types of check valves can be installed in pipeline systems intended for transportation of water.

Reverse petal valve is equipped with a special locking element - spring-loaded petal. A large disadvantage of the shutters of this type is that, when they are triggered, significant shock loads are created. This negatively reflects on the technical condition of the shutter itself, and may also cause the hydraulic impact in the pipeline system.
Reverse valve devices of two-dimensional type are characterized by compact sizes and a low weight.
The lifting coupling valve includes a spool freely moving along the vertical axis as a locking element. The work of the shut-off mechanism may be the gravitational principle when the spool returns to the closed state under the action of its own weight. Spring can also be used for this purpose. If you decide to install a gravitational check valve on the pipeline, keep in mind that you can install such a device only on vertical systems of the system. Meanwhile, the gravitational valve is characterized by the simplicity of the design, while demonstrating high reliability during operation.
There are check valves, the shut-off element of which is the spring-made metal ball. The surface of such a ball can be additionally covered with a layer of rubber.

Solving, what the reverse valve is better and is needed in the pipeline system an expensive shutter more complex designshould first get to know technical characteristics Such a device and compare them with the parameters of the pipeline system. The main purpose of the check valve, as mentioned above, is to pass water through the pipeline in right direction and not to give a flow of liquid to move in reverse side. In this regard, choose the return valve on the water follows from what pressure in the pipeline moves the flow of water. Naturally, it is necessary to take into account the diameter of the pipes that such a valve must be installed.

Performing the installation of the pipeline, you should also keep in mind that you can install the check valve different ways. In the pipes of significant diameter, the flange and interflant-type check valves are installed, and the coupling shutters are installed on the pipes of a small diameter. The weld method of installing check valves is used primarily when mounting on polypropylene and metal-plastic pipes.

If you select the right check valve and method of installing it, this device will not only serve for a long timeBut will ensure the correct operation of the entire pipeline system.

How to perform installation

Having understood with the question of why the return valve is needed, and with its role in the pipeline system, it is also necessary to explore the rules for its installation on the already operating or only created by the pipeline. Mounted such devices on different elements Pipeline systems:

on pipelines of autonomous and centralized water supply;
on suction lines serviced by deep and surface pumps;
in front of boilers, capacitive water heaters and water consumption counters.

If you are interested in check valves that can be installed both in vertical and horizontal position, choose not gravitational, and spring models. To learn about how the direction of water should move through the valve, can be moved by a special arrow applied to the device body. When installing feed valves of the coupling type for good sealing, be sure to use Fuma tape. In addition, we should not forget that reverse shutters need regular maintenance, so it is necessary to set them in the available places of the pipeline.

When installing the check valve on the suction line submersible pump You should take care that the filter is installed before such a device rough Cleaningwhich will not give to the inside of the device with mechanical impurities contained in underground water. As such a filter, a perforated or mesh clip can also be used, which is placed in the check valve installed at the inlet end of the suction line of the submersible pump.

When installing the check valve on the already running pipeline, you should pre-disable the system from water supply and only then engage in mounting the shutter.

How to independently make the check valve

A simple design of the check valve allows you to make it with your own hands if necessary.

To solve this task you will need the following materials and tools:

tee S. internal threadwhich will perform the function of the case;
coupling with carvings on the outer surface - the saddle of the self-made check valve;
rigid spring made of steel wire;
steel ball, the diameter of which should be slightly smaller than the diameter of the hole in the tee;
steel threaded plug, which will perform a function of the spring;
standard set of plumbing tools and sealing fum-tape.

5,00

The company "Nemen" sells safety valves designed to work in various environments. We offer, which can be installed vertically on the pipeline area or boiler aggregates.

Appointment of safety reinforcement

The safety valve is a form of fittings that is designed to automatically protect pipelines and equipment from exceeding pressure over a certain, predetermined value by resetting overweight working media. The valve also provides a discharge stop when restoring normal operating pressure. Safety valve is a direct valve fittings directly from the energy of the working medium.

Principle of operation of the safety valve

When the safety valve is in a closed state, the power pressure of the reinforcement is affected by the power pressure in the pipeline, which seeks to open the valve, as well as preventing the discovery force from the deposit. In the event of an occurrence in the system of perturbations provoking the increase in pressure of the medium over the worker, the prulchery force of the spool to the saddle decreases. When its value is zero, there is an equilibrium of active forces from the valve and the pressure of the medium simultaneously affecting the valve. If the pressure in the system continues to increase, the locking body opens and reset the excess medium through the valve. Reducing the volume of the medium leads to normalization of pressure in the system and disappearing of perturbing effects. When the pressure level falls below the maximum permissible, the locking body returns to its original position under the influence of force from the depositter.

Safety spring valves

In such safety valves, the springs compression force is used as counteraction of the pressure of the working medium. Due to the installation of various springs, the same safety spring valve can be used for several limits setting the maximum allowable pressure. In spring valves there is no seal on the stock. If the valve is installed in systems with an aggressive working medium, the spring is isolated using the glands, an elastic membrane or a bellows. The bellows seal is used in cases when the leakage of the working medium from the pipeline is unacceptable.

To reset the overpressure in the atmosphere, valves are applied safety springs, which are special pipe fittingsproviding reliable protection Pipeline from malfunctions and mechanical damage. The device is responsible for automatic reset of excess fluids, steam and gas from vessels and systems until the pressure is normalized.

Purpose of spring valve

Hazardous exceeding pressure in the system arises as a result of external and internal factors. In addition, it leads to the incorrect collection of heat-mechanical schemes, causing failures in the functioning of equipment, heat in the system from extraneous sources and intrasystems of physical processes that are not provided for by standard operating conditions periodically arising in the system.

Safety products - a mandatory part of any household or industrial system operating under pressure. Installation of safety mechanisms is carried out on pipelines in compressor stations, on autoclaves, in boiler rooms. Valves perform protective functions on pipelines for which not only gaseous, but also liquid substances are transported.

Device and principle of spring valves

The valve consists of a steel housing, the lower fitting of which is used as a connecting element between it and the pipeline. If the system increases pressure, the reset of the medium occurs through the side fitting. Adjected depending on the pressure in the spring system ensures the pressing of the spool to the saddle. The spring adjustment occurs by means of a special sleeve, which is screwed into the upper cover located on the device case. The hollows placed in the upper part is designed to protect the sleeve from destruction as a result of mechanical effects. The presence of a special ears for sealing allows you to protect the system from foreign intervention.

For valves, in which the spring, the spring is performed, the effort of the worker is selected. If the parameters are selected correctly, at the normal state of the system, the spool that is responsible for the release of excessive pressure from the pipeline must be pressed to the saddle. When the performance indicators increases to a critical level depending on the type spring device The spool moves up at a certain height.

Safety spring valve, providing a timely discharge of pressure, is made from different materials:

Carbon steel. Such devices are suitable for systems, the pressure in which dwells in the range of 0.1-70 MPa.
Stainless steel. Valves out of stainless steel Designed for systems, the pressure in which does not exceed 0.25-2.3 MPa.

Classification and characteristics of spring valves

The valve safety spring is available in three versions:

Lightweight devices Suitable for gas pipelines and steam pipelines, the pressure in which does not exceed 0.6 MPa. The height of the lift of such a valve does not reach more than 1/20 diameter of the seat
Mid-lining devices, in which the height of the lifting of the spool is from 1/6 to 1/10 from the nozzle dimer.
Full-dimensional devicesin which the lifting height of the valve reaches up to ¼ from the saddle diameter.

Known classification of valves based on the method of their opening:

Reverse spring valve. To control inverse spring valves, an indirect foreign source of pressure is involved. Inverse spring valveswhich is called pulsed safety devices can operate by exposure to electricity.
Direct valve. In devices direct type The operating pressure of the medium has a direct effect on a spool, which rises with the increase in pressure.

Highlight valves open and closed type . In the case of using a direct type device when the valve is opened, the medium is reset directly into the atmosphere. Closed-type valves remain completely sealed with respect to environmentdropping pressure into a special pipeline.

Benefits

Different types of equipment that provides reset output from the system, but safety sprocket valves are popular due to the presence of important advantages:

Simplicity and reliability of the design.
Easy to configure operating parameters and ease of installation.
A variety of sizes, types and constructive versions.
Installation of the safety product is possible both in horizontal and vertical position.
Relatively small overall dimensions.
A large passage section.

By the cons of safety valves include the presence of restrictions in the height of the lifting of the spool, increased requirements for the quality of the manufacture of spring for safety valves, which may fail when working under the aggressive medium or constant exposure to high temperatures.

How to choose a spring valve?

When choosing a fuse should be based on several important principles, on which the uninterrupted operation of the system and the ability to execute the necessary functions are depends on:

Safety spring valves have the smallest dimensions compared to other types of fuse valves of waste, so they should be chosen in cases where free space is not enough.
The features of the application of valves are associated with the presence of increased vibrations that adversely affect performance features Devices and can quickly lead it into disrepair. For example, lever-cargo type devices are more susceptible to breakdowns due to the effects of vibrations due to the presence in the design of a long lever with weight and hinges. Therefore, for systems in which significant vibrational impacts are observed, it is worth choosing a safety spring valve.
Depending on the design features of the device, the spring can change the pressure force over time. This is due to the fact that the constant rise of the spool causes changes in the structure of the metal.

Nuances of Montaja

Spring-type safety valve is installed at any point of the system that is exposed. increased pressure And it is threatened to obtain mechanical damage. The device does not require the presence of a large free space, which is a significant advantage compared to other types. safety devices.

In order to avoid troubleshooting before the safety valve, you should not install any locking reinforcement. To reset the gaseous medium, special devices are installed or the discharge occurs directly into the atmosphere. To alert personnel, together with spring valves, a special whistle is assembled, which is placed on a dumping nozzle. When the valve is triggered, the whistle signal will flow, meaning that the system has increased pressure and the valve opened to reset the medium.

Possible causes of safety valve breakdowns

Safety valves are strong and reliable devices that provide constant protection of systems from exceeding pressure. Direct or reverse spring valve fail for several reasons:

The presence of increased vibrations;
Continuous impact of the aggressive environment on a safety choke.
Incorrect installation of a safety spring choke or valve.

In order to avoid accidents and malfunctions in the operation of systems, safety valves pass periodic verification for problems. Valves are tested for strength and density before commissioning. Periodic checks are carried out in order to determine the tightness of the sealing surfaces and the sloping compounds.

For proper choice Safety devices based on system parameters, conducting periodic inspections and timely troubleshooting safety sprocket valves will ensure reliable operation of the system and trouble-free protection against excess pressure over a long time.

Each node of the pipeline system plays an important role in ensuring its performance. For example, the safety spring valve is a pipe fittings needed to protect against destruction when an overpressure in the pipeline appears. This is possible due to the release of the environment from the system.

Another spring valve provides a discontinuation of the medium, when working pressure will be within the normal range.

Features and principle of operation

Surgent type safety valve - direct valve, which functions from the medium. Where in the system may appear overpressure? As a rule, the reason lies in the external and internal factors:

incorrect thermal mechanical scheme;
heat transfer from sources;
incorrect equipment functions.

Spring safety coupling valve is installed everywhere on the ground, where there is a risk of excessive maximum pressure. As a rule, these are household or industrial accumulative vessels operating under pressure.

Much popularity of this reinforcement provides simple design, Easy settings, product range. After all, such a variety and opportunities allow you to pick up optimal model For specific conditions.

Installation of the safety choke is performed vertically. The device of the spring flange safety valve implies the use of a disk shutter as a locking element, which is placed between the saddle when locking.

The clamping force is set using a special device and springs for safety valves.

When the pressure is very large, the specified clamping force is not enough to hold back the medium, so the surplus is removed until the pressure levels up to the working level.

The passport on the valve safety spring allows you to learn about the product of the product. The main components are a master and locking authority. The latter consists of a saddle and shutter.

With the help of the master, it is adjusted so that the spool is properly pressed to the saddle to obstruct the passage of the environment. The setting is performed by screw.

The closing pressure of the shutter is usually taken below for 10 percent.

Classification of products

Consider what types of safety products exist.

By the nature of the climbing authority:

two-position;
proportional action.

In the height of the lift of the authority:

full-dimensional;
mid-lining;
littered.

By type of load on the spool:

freight;
magneto-spring;
lever-spring;
spring-.

According to the principle of action:

direct - traditional safety products;
indirect action - pulse devices.

One of the modifications widely used in the industry is an angular safety spring choke.

Another principle of classification - according to the conditional diameter. For example, if the reverse spring valve D15 is used - it means that the conditional diameter is 15 mm, and the reverse spring coupling choke DU50 is 50 mm.

Product specifications

Payment bandwidth Performed according to GOST 12.2.085. Devices can be used in petroleum, chemical, gaseous and liquid medium. Tightness is determined by GOST 9789-75.

The pressure closure pressure is more than 0.8 pH, wherein the pH is the pressure of the setting, is the largest in the inlet to the valve, in which it remains in a closed state, while the proper tightness is observed.

Springs for them are made most often from steel 50xf. Spring check valve Type 402 is made of cast iron.

To test the serviceability of the device in working condition, the spring safety valve SPPK has a solution for manual opening, purge, therefore, products without SPPK do not have the possibility of manual opening.

The dimensions of the sealing surfaces of the flanges are determined by GOST 12815-80.

As an example, one of the modifications of the device we present the fuse 17c28nzh, corresponding to T3742-017-00218118-2002.

The device has characteristics:

operating pressure - 1.6 MPa;
working medium - non-aggressive, gas, steam, water;
case material - steel;
sealing coating material - stainless steel;
connection - flange;
temperature - from minus 40 to plus 250 degrees;
mass and length depend on the conditional diameter.

Child Nuances

To choose optimal product, It is necessary to take into account the requirements that are presented to them:

timely and trouble-free device safety valve With the indicated increase in the level of working pressure in the system;
in the open position, the necessary bandwidth must be provided;
timely closure of the shutter with the desired level of tightness;
ensuring stable work.

An important value has a cost when choosing. For example, let's look at how much can I buy a safety spring valve 17c28nzh: the price for the reverse coupling spring choke is from $ 300.

Of course, much depends on the manufacturer. So, a similar reverse spring valve Danfoss will cost more - from $ 400.

Features of the product (video)

Nuances of Montaja

Before installing a safety spring valve, simple actions should be performed:

check markings;
inspect the housing for external damage;
remove the protective cap;
inside there are no foreign objects;
it should be remembered that when installing the components will be heated.

The installation process is performed in accordance with the current safety regulations and regulatory and technical standards. The choice of place, design and number of valves, as well as the direction of resetting the medium, is determined by the project.

The place must be selected so that there is free access for maintenance and repair. Installation is performed in a vertical position at the top point of the vessel. Also, the installation can be performed near the vessel or pipeline, only a shut-off body should be present between the products.

The size of the fitting can not be less than the diameter of the inlet nozzle valve.

Reverse spring plate valve with large number Plate can provoke an increase in their resistance, which is capable of changing the pressure difference in the upper and cubic parts of the product. Therefore, it is worth installing it in the last area.

Independent installation of such devices is a complex procedure requiring experience and certain skills. Therefore, it is necessary to contact professionals.

Problems and repair

The leakage of the medium through the shutter occurs when the pressure occurs below, rather than the installation.

delay in sealing elements of foreign objects - it is necessary to perform a throttle blowing;
damage to sealing elements - Performance or tread is performed followed by tightness testing; If the depth of damage is more than 0.1 mm, it is necessary to perform mechanical processing;
spring deformation - its replacement is performed;
violation of the alignment of elements due to a large load - the load is eliminated, the discarded and receiving highway is checked, it is necessary to perform a drawing of studs;
reduced opening pressure - adjustment, springs deformation - its replacement is performed;
the poor-quality assembly after repair is to eliminate all the shortcomings of the assembly.

Repair of safety spring chokes must be trusted to professionals. The cost of the procedure will cost $ 50.