PZK gas with hammers work principle. Safety-lock valves PZK. Safety-reset valve PSK

Safety devices are divided into shut-off and dumping. Protective-locking devices (shut-off valves) - devices providing the cessation of gas supply, in which the speed of bringing the working body into the closed position is not more than 1 sec. Safety-reset devices ( upset valves) - Devices providing protection for gas equipment from an invalid increase in gas pressure on the network.

Safety-locking devices are installed in front of the gas pressure regulator. Their membrane head through the pulse tube is connected to the gas pipeline of the final pressure. With an increase in the final pressure over the established norms, the PZK automatically complies with the supply of gas to the regulator.

Safety-dumping devices used in GPP provide reset of an excessive amount of gas in the event of a loose closure of the PPC or the regulator. They are mounted on the discharge pipe of the gas pipeline of the final pressure, and the output fitting is connected to a separate candle. If a technological process Gas consumers provide continuous operation gas burners, then the PZK is not installed, and only PSK is installed. In this case, it is necessary to establish gas pressure signaling devices that inform about increasing gas pressure over a valid value. If the GRP (GRU) supplies dead-end objects with gas, then the installation of the PZK is necessary.

Consider the most common types of shut-off and safety devices.

Low PGK (PKI) and High Pressure (PKV) control the upper and lower limits of the output pressure of the gas; Release with conditional passages 50, 80, 100 and 200 mm. The PKV valve differs from the PCN valve by the fact that it has an active area of \u200b\u200bthe membrane due to the overlay of the steel ring on it.

Schematic scheme These valves are presented in Figure below.

PCN and PKV Safety Valves

1 - fitting; 2, 4-levers; 3, 10- pins; 5 - nut; 6 - plate; 7, 8 - springs; 9 - drummer; 11 - rocker; 12 membrane

In the open position, the valve is held by the lever, which is fixed in the upper position behind the hook of the anchor lever; The drummer with the help of the pin rests in the rocker and is held in a vertical position.

The pulse of the final gas pressure through the fitting is supplied to the subable space of the valve and has a back pressure on the membrane. The movement of the membrane is preventing the spring. If the gas pressure rises over the norm, the membrane moves up and the nut will move accordingly. As a result, the left end of the rocker will move upwards, and the right drops and will come out of the tint with the pin. Drummer, freed from engagement, falls and hit the end of the anchor lever. As a result, the lever is derived from the engagement with the pin, and the valve will block the gas pass. If the gas pressure drops below the permissible norm, then the gas pressure in the subable valve space becomes less than the force generated by the spring, resting on the rod of the membrane rod. As a result, the membrane and rod with the nut will go down, fascinating the end of the rocker down. The right end of the rocker will rise, will come out of the engagement with the pin and cause the drop in the drummer.

Recommended next order Settings. First, the valve is adjusted to the lower limit of the trigger. During configuration, the pressure behind the controller should be maintained slightly above the set limit, then slowly reducing the pressure, make sure that the valve is triggered with the installed lower limit. When setting up the upper limit, it is necessary to maintain a slightly larger lower limit pressure. At the end of the setting, it is necessary to increase the pressure to ensure that the valve is triggered at a given upper limit of the permissible gas pressure.

Safety-shut-off valve PKK-40M.

In the cabinets (drawing below below), a small-sized PKK-40M PKK-40m PCC is installed. This valve is designed for 0.6 MPa inlet.

Scheme of the strapping of cabinet GRU with PKK-40m PKK

a - Schematic diagram: 1 - entrance fitting; 2 - input valve; 3 - filter; 4 - fitting for pressure gauge; 5 - Valve PKK-40M; 6 - regulator RD-32M (RD-50M); 7 - Final pressure measurement fitting; 8 - output valve; 9 - discharge line built into safety valves; 10 - pulse line finite pressure; 11 - Pulse line; 12 - fitting with a tee; 13 - manometer; b - incision of the PKK-40M valve: 1, 13 - valves; 2 - fitting; 3, 11 - springs; 4 - rubber seal; 5, 7 - holes; 6, 10 - membranes; 8 - launcher; 9 - Pulse chamber; 12 - stock

To open the valve, you unscrew the starting plug, after which the valve pulse chamber is communicated with the atmosphere through the hole. Under the action of the gas pressure of the membrane, the rod and the valve move upwards, when the membrane is in the extreme upper position, the hole in the valve rod is covered with rubber seal and gas flow from the housing in pulse chamber stops. Then the starting plug screws. Through open valve Gas enters pressure regulators and on the pulse tube to the chamber. If the gas pressure behind the regulators is boosting over the mounted limits, the membrane, overcoming the elasticity of the spring, moves up, resulting in a hole, covered by a previously rubber seal, will open. The upper membrane, lifting, rests on his disk in the lid, and the bottom under the action of the spring and the valve mass with the rod drops down, and the valve closes the gas passage.

Valve Safety-shut -tented BPP (Figure below) is installed in front of the gas pressure regulator. Its upper response limit should not exceed the nominal working pressure after a regulator by more than 25%, and the lower response limit in the rules is not set, since this value depends on the pressure loss in the supply gas pipeline and on the control range.

Valve Safety-shut -tented BPP

1 - body; 2 - valve with rubber seal; 3 - axis; 4, 5 - springs; 6 - lever; 7 - control mechanism; 8 - membrane; 9 - rod; 10, 11 - Springs settings; 12 - emphasis; 13, 14 - sleeves; 15 - tip; 16 - lever

The principle of operation of the CPP is as follows:

in the working position, the valve levers in the engagement and in the stop with the tip of the rod of the membrane head, and the valve of the KPZ is open;
when the gas pressure changes above or below the permissible membrane, the rod is bent and moves the rod, respectively, change the pressure to the right or left together with the tip;
the lever comes out of touch with a tip , At the same time, the engagement of the levers is disturbed and the axis closes the valve under the action of the springs;
the inlet gas pressure goes to the valve and closely presses it to the saddle.

Reliable safety devices In contrast to the shut-off, do not overlap the supply of gas, and discharge its part into the atmosphere, due to which the pressure in the gas pipeline is reduced.

There are several types of discharge devices, various designs, the principle of operation and application field: hydraulic, lever-cargo, spring and membrane-spring. Some of them apply only for low pressure (hydraulic), others - both for low and for average pressure (membrane-spring).

Safety-reset valve PSK. The membrane-spring claim (Figure below) is installed on low and medium-pressure gas pipelines. PSK-25 and PSK-50 valves are different from each other only by dimensions and throughput.

Safety-reset valve PSK

1 - adjusting screw; 2 - spring; 3 - membrane; 4 - seal; 5 - spool; 6 - saddle

Gas from the gas pipeline after the regulator enters the valve membrane. If the gas pressure turns out more spring pressure from below, the membrane moves down, the valve opens and the gas goes to reset. As soon as the gas pressure becomes smaller than the spring force, the valve closes. Spring compression is regulated by a screw at the bottom of the case. For the installation of PSK on low or high pressure gas pipelines, appropriate springs are selected.

PSK-25 reset valve spool has a cross-25 shape and moves inside the saddle, the valve spool is equipped with profiled windows. The reliability of the work of the PSK valve largely depends on the quality of the assembly.

When assembling it is necessary:

cleaning the valve device from mechanical particles, make sure that there are no scratches or tape rubber on the edge of the seat and sealing rubber;
achieve the alignment of the location of the spool valve with the central hole of the membrane;
to check the alignment to weaken or remove the spring and by pressing the spool through the reset hole, make sure that it is freely moving inside the saddle.

Safety and reset valve PPK-4.

Spring Safety Valve Middle and high pressures PPK-4 (Figure below) is produced by industry with conventional passages 50, 80, 100 and 150 mm. Depending on the diameter of the spring 3, it can be adjusted for a pressure of 0.05-2.2 MPa.

PPK-4 PPK-4 FAST

1 - valve seat; 2 - spool; 3 - spring; 4 - adjusting screw; 5 cam

Gas filters.

In the GRU with a conditional passage up to 50 mm, the angular mesh filters (Figure below) are installed, in which the filter element is a clip, covered with a small grid. In the hydraulic power plant with regulators with a conditional passage, more than 50 mm applied cast-iron hair filters (figure below). The filter consists of a housing, covers and cassettes. The cassette clip on both sides is covered with a metal grid, which delays large particles of mechanical impurities. Smaller dust settles inside the cassette on the extruded fiber, which is lubricated with special oil.

Gas filters

a - corner net; B - hair: 1 - case; 2 - cover; 3 - grid; 4 - extruded fiber; 5 - Cassette

The filter cassette has a gas stream resistance, which causes pressure drop to the filter and after it. Increasing the gas pressure drop in the filter of more than 10 LLC PA is not allowed, as this can cause fiber deposits from the cassette.

To reduce the pressure drops, the filter cassettes are recommended to be periodically cleaned (outside the GPT building). The internal cavity of the filter should be wiped with a cloth moistened in kerosene.

Depending on the type of gas regulators and pressure, various filter designs are used.

The figure below shows the filter device designed for hydraulic fracturing equipped with Rhduk regulators. The filter consists of a welded housing with connecting pipes for the input and gas output, covers and plugs. From the part side of the gas inside the hull is welded a metal sheetprotecting the grid from directly entering solid particles. Solid particles coming with gas, hovering into a metal sheet, are collected at the bottom of the filter, from where they are periodically removed through the hatch. Inside the case there is a mesh cassette filled with a caproove thread.

Welded filters

a - filter to Rhduk regulators: 1 - welded body; 2 - upper cover; 3 - cassette; 4 - Luke for cleaning; 5 - jackhamge; B - filter revision: 1 - outlet; 2 - grid; 3 - body; 4 - Cover

The solid particles remaining in the gas flow are filtered in the cassette, which is cleaned as necessary. For cleaning and washing the cassette, the top cover of the filter can be removed. Differential pressure gauges are used to measure the pressure drop. Additional filtering devices are installed before rotary counters - the filter revision (figure above).

Laboratory work number 11

Purpose of work:Explore the appointment, the device and the principle of operation of the gas regulatory item, as well as detail with all the nodes and the units of the incoming in it. Examine the gasket of the internal gas pipelines and connect them to the boilers.

Fig.3.1. Schematic diagram of a gas regulatory item:

1 - Safety-dumping valve (reset device); 2 - valve on the bypass line; 3 - Pressure gauges: 4 - Pulse PZK line: 5 - purge gas pipeline; 6 - bypass line; 7 - flow meter; 8 - laughter or entrance; 9 - filter; 10 - Safety-shut-off valve (GIC); 11 - pressure regulator; 12 - Having drive at the exit.

Gas regulatory items (GPP)designed to reduce the input gas pressure to a specified output (working) and maintain it constant, regardless of changes in the input pressure and gas consumption. Gas pressure fluctuations at the exit of hydraulic fracturing are allowed within 10% of the operating pressure. In addition, the GPP is carried out: gas purification from mechanical impurities, control of input and output pressure and gas temperature, protection against increasing or decrease in gas pressure for hydraulic gas, gas consumption.

On the PPP scheme shown in Fig.3.1, three lines can be distinguished: basic, water-based (bypass) and working. On the basic lines gas equipment Located in the following sequence: inlet locking device (valve 8 ) To disable the main line; Purgery gas pipeline 5 : Filter 9 for gas purification from different mechanical impurities; Safety shut-off valve 10 , automatically turning off the gas supply when increasing or decrease in the gas pressure in the working line for the set limits; Regulator 11 gas pressure, which reduces gas pressure and automatically supports it at a given level, regardless of the gas consumption; Output locking device 12 .

Bypass (from English bypass - bypass) line make up the purge gas pipeline 5, two locking devices (valves 2), which are used for manual gas pressure control in the working line during execution repair work On the main line disconnected.

On the working line (the operating pressure line) is set to a waste-reset valve 1 (PSK), which serves to reset the gas through a dumping candle into the atmosphere while increasing gas pressure in the working line above the established limit.

The following control and measuring instruments are installed in the hydraulic instrumentation: thermometers for measuring gas temperature and indoors ; flow meter 7 gas (gas meter, throttle flow meter); Manometers 3 To measure the input pressure of the gas and pressure in the working line, the pressure at the inlet and outlet of the gas filter.

Gas filters.Filters are designed to purify gas from mechanical impurities: dust, rust and various inclusions contained in gas. Gas purification is necessary to reduce wear of the shut-off and regulating reinforcement, prevent clogging of pulse tubes, throttle holes, protection of membranes from premature aging and loss of elasticity, etc.

Depending on the cost of gas, its pressure, the type of regulators apply various filter designs.

Fig. 3.2. Gas filters:

but - corner net; b. - hair; in - welded; 1 - body; 2 - clipping; 3 - traffic jam; 4 - cassette; 5 - lid; 6 - jackhamge; 7 - Luke for cleaning.

In the hydraulic fracturing, placed in the cabinets, and in the PPPs with the diameter of pipelines up to 50 mm, angular mesh filters are installed (Fig. 3.2. but).The filter consists of a housing / filtering element - clutch 2, covered with shallow metal grid. The gas in the inlet pipe enters the filter element, is cleaned there from dust and on the outlet nozzle comes out of the filter. Dust particles are deposited on the inner surface of the metal grid. For the revision of the filter and its replacement is provided 3, you can remove the filter element from the housing.

In the hydraulic pipelines with a conditional diameter of 50 mm pipelines and pig-iron hair filters are more widely used (Fig. 3.2, b).The filter consists of the housing /, covers 5 and cassettes 4. Cleaning gas from dust occurs in a wire mesh cassette, between which the horse hair is located or a caproove thread. The filter material is impregnated with whiscin oil. On the output side of the cassette, the perforated sheet is installed, protecting the rear (in the gas) mesh from the rupture and deployment of the filter material.

Welded filters (Fig. 3.2, in)designed for GPP with gas flow from 7 to 100 thousand m 3 / h. The filter has a welded body 1 with connecting nozzles for the input and gas output, cover 5, hatch 7 for cleaning and cassette 4, filled by kapron thread. From the side of the gas entrance inside the hull welded a jackham 6.

Large particles, getting into the filter, hit the jackhamble sheet, lose speed and fall on the bottom. Small particles are tracked in a cassette with a filter material impregnated with whiscin oil.

In the process of operation, the aerodynamic resistance of filters increases. It is defined as a gas pressure difference at the inlet and outlet from the filter. The gas pressure drop on the cassette should not exceed the value established by the manufacturer. The disassembly and cleaning of the cassette is carried out during maintenance outside the PPP premises in places removed from flammable substances and materials at least 5 m.

Protective valves. The most common safety-lock valves are low (PCN) and high (PKV) pressure valves, produced with a conditional passage of 50, 80, 100 and 200 mm. They are installed in front of the pressure regulator. The designs of PKN valves and PKV are almost the same.

Safety-shut-off valve PKN and PKV (Fig. 3.3) consists of a cast-iron cast case 4 valid type, membrane chamber, tuning head and lever systems. Inside the case there is a valve 5 . Valve rod enters the connection with the lever 3, one end of which is fastened to be hinged inside the case, and the other with the cargo is removed. For opening valve 5 With the help of lever 3 it is necessary that at first a little rose a rod and that the rod was held in this position. This opens the hole in the valve and the pressure drop before and after it decreases. Lever arm 3 the load is introduced with one of the ends of the anchor lever 6, which is strengthened on the hinge housing. Impact hammer 1 It is also attached to be hinged and located over another free shoulder of anchor lever.

Figure 3.3. Safety-shut-off valve Low (PCN) and high

(PKV) Pressure:

1 - shock hammer; 2 - pin of the lever; 3 - lever with cargo; 4 - body; 5 - valve; 6 - anchor lever; 7 - socket; 8 - membrane; 9 - Large tuning spring; 10 - Small tuning spring; 11 - rocker; 12 - Pin

Above the housing under the tuning head is a membrane chamber in which through the fitting 7 Paul membrane 8 gas pressure impulse from the working line. On the membrane from above there is a rod with a socket, which includes a rocker in one shoulder 11 . Other Krug's shoulder comes in engaging with a pint 12 shock hammer.

If the pressure in the working gas pipeline exceeds the upper limit or it is lower than the lower specified limit, then the membrane mixes the rod, pulling out of the engagement pin of the shock hammer with a rocker. The hammer at the same time falls, hits the anchor lever on the shoulder and removes his other shoulder from the engagement with the lever with the cargo. Under the action of cargo, the valve is lowered and the gas supply stops. To adjust the safety valve to the upper limit of the trigger, a large tuning spring is used. 9 , and on the lower limit of the trigger - a small tuning spring 10.

Safety-shut-off valve KPZ (Fig. 3.4) consists of a cast case 4, valve 3 assigned to the axis 1 . On axis 1 Springs 2 installed, one end of which rests on the housing 4, and the other - in the valve 3. At the end of the axis 1 leaving the lever 12. which through the intermediate lever 13 S.emphasis 14 hold in a vertical position tip 15 mechanism of control 10. The control mechanism includes a membrane 11 , stock 5 and fixed on the rod tip 15. The membrane is equalized by controlled pressure and springs 8 and 9., the efforts of which are regulated by threaded bushings 6 and 7 .

Fig. 3.4.:Besertion-resistant Valve CPZ:

1 - axis; 2,8,9 - springs; 3 - valve; 4 - Case: 5 - stock: 6,7 - sleeves; 10 - control mechanism; 11 - membrane; 12, 13 - levers; 14 - emphasis; 15 - Tip

When the gas pressure increases or decreases in the subable area relative to the limits of the tip setting, the tip moves to the left or right and emphasis 14. established on the lever 13, comes out of the engagement with the tip 15. releases related levers 12 and 13 and gives the ability to axis 1 sprocket 2 . At the same time the valve 3 closes gas passage.

The upper limit of the triggering of safety valves should not exceed the nominal operating pressure of the gas after a regulator by more than 25%. The lower limit is determined by the minimum permissible pressure specified in the duct passport, or pressure, in which the burners can go out according to the device testing, the flame is accumulated.

Pressure regulators.In terms of indirect action pressure regulators, in which gas pressure regulation occurs by changing its consumption, and control is carried out due to the energy of the gas itself. Continuous-acting regulators with amplifiers (pilots), such as Rnuk-2, were the greatest distribution.

Pressure regulator Universal F.F. Kazanzva Rnuk-2 consists of a controller itself and a control regulator - a pilot (Fig. 3.5).

Gas urban (input) pressure through filter 8 punch tube BUTenroll in the capacked space of the pilot. The power of its pressure is pressing valves (plungers) 2 and 9 (regulator and pilot) to saddles 7 and 10. At the same time, the gas does not enter the working gas pipeline and there is no pressure in it. To start a pressure regulator to work, you need to slowly screw the glass 4 in the body of the pilot. Spring 5 , compressing, affects the membrane and overcomes the power of the gas pressure in the caplap space of the pilot and the spring force 1 . The pilot valve opens, and the gas from the caplapped space of the pilot enters the sublink and then on the connecting tube B.through choke 12 under the membrane 11 regulator. Part of the gas through the choke 13 reset to the working gas pipeline, but pressure under the membrane of the regulator is always somewhat larger than the pressure in the working gas pipeline. Under the influence of pressure drop under and over the membrane 11 The latter regulator is raised, opening the valve 9 regulator, and gas will come to the consumer. The glass of the pilot is screwed until the pressure in the output gas pipeline becomes an equal to the specified worker.

Fig. 3.5. Scheme of the pressure regulator of the universal F.F. Kazanseva Rnuk-2:

1, 5 - springs; 2 - pilot valve; 3 - a pen; 4 - Glass; 6 - Pilot membrane; 7, 10 - saddles; 8 - filter; 9 - valve of the regulator; 11 - membrane of the regulator; 12, 13 - chokes; A B C D E - Tubes

When changing the gas flow rate at the consumer, pressure changes in the working gas pipeline. Thanks to the pulse tube INchanges and pressure over the membrane 6 pilot, which, dropping and squeezing the spring 5 or lifting under the influence of the spring, is appropriately covered or open the pilot valve 2.

This reduces or increases the supply of gas through the tube used under the pressure regulator membrane. For example, with a reduction in gas spending by the consumer, the pressure in the working line increases, the pilot valve 2 is covered and the valve 9 of the regulator also hits, restoring the pressure in the working gas pipeline to the specified one. With increasing flow and reduction of the pressure of the pilot valves and the regulator, the pressure in the working gas pipeline rises to the specified one.

Safety-dumping valve. In fig. 3.6 shows the PSK-50 dumpling valve, which consists of a housing 1 , Membranes 2 With a plate on which the plunger is strengthened (valve) 4 , tuning spring 5 and adjusting screw 6 . With a working gas pipeline, the valve is reported through the side nozzle. With increasing gas pressure above a certain adjustment spring 5 Squeezing, membrane 2 together with the plunger is allowed, opening the yield of gas through a discharge pipeline into the atmosphere. When the pressure decreases the plunger under the action of the spring overlaps the saddle, the discharge of the gas stops.

Safety-dumping valve (PSK) is installed behind the pressure regulator; If there is a flow meter - behind him. Before PSK, a disconnecting device is installed, open during normal operation and used when repairing PSK.

Fig. 3.6.Chentable-50 PSK-50 dumping valve:

1 - body; 2 - membrane with a plate; 3 - lid; 4 - plunger; 5 - spring; 6 - Adjusting screw.

Control and measuring devices in GPP. To measure the input and output pressure and the gas temperature in GPA, we establish showing and registering control and measuring instruments (KIP). If the gas flow rate is not carried out, the absence of a recording instrument is allowed for measuring the gas temperature.

The drug with an electric output signal and electrical equipment indoors are provided in the explosion-proof version.

The drug with an electrical output signal in normal design is placed outside in a closing cabinet or in a separate room, attached to the fire-fighting gas-tight hydraulic grip.

Requirements for the premises of the PPE. GPP gas regulatory points are arranged in accordance with construction standards and rules (SNiP). They are forbidden to embed or add to public, administrative and household buildings of an unprofitable nature, as well as place in the basement and basement of buildings. Separate buildings used to accommodate GPUs must be single-storey I and II degrees of fire resistance with combined roof. Floor material, the device of windows and doors of the PSE premises should exclude the possibility of forming sparks.

In the PPP premises, natural and artificial lighting and natural constantly active ventilation, providing no less three-time air exchange in 1 h. Air temperature in GPP must comply with the requirements specified in the equipment passports and instrumentation. The width of the main passage in the hydraulic passage of the hydraulic passage should be at least 0.8 m. In the premises of the PPP, the installation of a telephone apparatus in an explosion-proof version is allowed. The door in the GDP should open out. Outside the GDP building should be a preventive inscription "Flameless Gas".

Domestic gas pipelines. Domestic gas pipelines are performed from steel pipes. Pipes are connected by welding, detachable connections (flange, threaded) are allowed to install fittings, devices, instrumentation and dr.

Gas pipelines are laid, as a rule, openly. Hidden wiring It is allowed in furrows of walls with easily removed shields with ventilation holes.

Gas pipelines should not cross ventilation grates, window and doorways. In places of passage of people, the gas pipelines are laid at an altitude of at least 2.2 m. Pipes are attached using brackets, clamps, hooks and suspension.

It is forbidden to use gas pipelines as support structures, grounding. Gas pipelines are painted waterproof paint and varnish materials yellow color.

Fig.3.7. The diagram of the internal gas pipelines boiler room and the location of the disconnecting devices:

1 - case; 2 - a general disconnecting device; 3 - Crane on purge gas pipeline; 4 - fitting with a crane for taking a sample; 5 - purge gas pipeline; 6 - pressure gauge; 7 - Inspesting manifold; 8 - branch to boiler (omitting); 9 - Disconnecting device on omitting.

The schematic diagram of the internal gas pipelines with a few boilers is shown in Fig. 6.8. Gas in the introductory gas pipeline passes through the case installed in the wall of the boiler room. Case 1 is made of segment steel pipe, inner diameter which is at least 100 mm larger than the diameter of the gas pipeline. The case provides an independent sediment of walls and gas pipelines. The total disconnecting device 2 is designed to disable all boilers with a planned or emergency shutdown of the boiler room. Disconnecting devices 9 on branches 8 to boilers (omens) are designed to disconnect individual boilers.

Fig. 6.9. Scheme of the location of the gas equipment of the gas equipment with two burners:

1 - gas collector; 2 - branch to the boiler (dug); 3 - disconnecting device on omund; 4 - PPC on the boiler; 5 - regulating gas damper; 6 - gas stall; 7 - zoom in front of the burners;

8 - burners; 9 - purge gas pipeline; 10 - Crane on purge gas pipeline; 11 - Crane to a manometer; 12 - manometer

The layout of the locking devices of the gas equipment of the boiler with two burners is shown in Fig. 6.9. Gas from distribution gas collector Boiler 1 in the branch to the boiler (descending) 2 passes through the disconnecting device 3 on the omission, the safety-shut-off valve 4 (PZK), adjusting the gas flap 5 and the locking devices 7 (memory) enters the burner 8.

For internal gas pipelines and gas equipment should be provided maintenance at least once a month. Maintenance Must be carried out at least once every 12 months in cases if there is no operation resource in the manufacturer's passport and there is no data on its repair.

Before repairing gas equipment, inspection and repair of furnaces or gas ducts, as well as when the seasonal operations are output, gas equipment and warehouse pipelines must be disconnected from gas pipelines with the installation of the plugs after the locking equipment.

Control questions:

1. How are gas networks in the magnitude of gas pressure are classified?

2. What gas pipelines are distribution, introductory and internal?

3. What materials are used in the construction of gas pipelines?

4. What methods are used to protect steel gas pipelines from corrosion?

5. Specify the assignment of the hydraulic PPP?

6. Where are the PPP?

7. Transfer the main elements included in the hydraulic fracturing?

8. Here purpose, the device and principles of the operation of the gas filter in the hydraulic fracture.

9. How to determine the degree of cloghood of the filter?

10. Purpose the purpose, device and principle of action of a PCN type safety valve (PKV), kPZ?

11. What are the assignment of the RDUK-2 pressure regulator, its device and the principle of operation?

12. Clean the purpose, device and principle of the action of the PSK-50 type valve valve?

13. Word the basic requirements for kip?

14. Word the basic requirements for PPP premises?

15. What are the basic rules for laying internal gas pipelines?

Safety shut-off valve PZK is configured to trigger when output of the pressure of the environment formaximum or minimum set value. Range of settingsit is listed in the operational instructions on the product.

Device requiredcome in the set of equipment gas distribution pointsto stop supplying gas to the consumer system in case of deviation operating pressure from establishedvalues \u200b\u200bI.

Protection of regulators, pressure gauges, counteroV and other exploited gas devices. Wherein resume gas supply can only service staff, after removing the reason that caused Warning valve I. Termination of gas flow to consumers.

When the gas pressure on the burners, the flame may occur on the burners of the instruments above the allowed limit What will entailgas supply to the room or working chambers and installations of installations By creating conditions for which the danger of the explosion occurs. To prevent such situations, the PZK valve is used, which cuts out the supply of gas in the case of a critical increase in pressure. The design of the product also provides triggering in case of no less dangerous, significant reduction in working pressure, as it may occurroscok of the flame in the nozzle burners, which will lead to incomplete combustion of gas And it can enddestruction i eat burners themselvesif burning gas continueinside them and will not be immediately discontinued.

To ensure the normal functioning of the product it is necessary Install directly in front of the gas regulators. At the same time, M aximal trigger pressure which must be configureddepends on the magnitude of the maximum allowable pressure for used gasnetwork. The minimum trigger pressure is determined by the pressure size below. There is a danger of interruption inwork gas appliances and installed to.Reasons oh unacceptable increase or decrease in gas pressure after a regulator for dead-end networks can be: a pressure regulator malfunction (plunger jamming, the formation of hydrate plugs in a saddle and a housing, shutter defectiveness); Incorrect selection of the regulator by its bandwidth, leading to the two-position mode of its operation at low gas flows and causing output pressure and auto-oscillation bursts.

The reason for an invalid increase or decrease in gas pressure after the regulator for ring and branched networks can be: a malfunction of one or more pressure regulators that feed these networks; Incorrect hydraulic network calculation, due to which the jump-like changes in gas consumption by large consumers lead to output pressure splashes.

The general reason for a sharp decline in pressure for any networks may be a disruption of the tightness of gas pipelines and reinforcement, and therefore gas leakage.

After incorporation Gas distribution point To work, check the density of the compounds with soap solution and detected leaks immediately eliminate.

Safety shut-off valve must be configured in such a way to work with a slightly larger pressure thanupset valve. However, its value should not be higher than the maximum permissible working pressure of the gas, in which the normal operation of gas-burner devices is ensured. P racking products for accuracy settings and the triggering is made as follows: it is necessary to graduallyincrease sit or lowerpressure , watchingwith what pressure valve will work. If the pressure matches the specified, the valve setting is left unchanged. Otherwise, it is necessary to adjust. When checking the valve, the gas must be supplied by bypass line.The setting is carried out on the pressure exceeding the final (behind the controller) at the pulse selection point by 25 to 50%, but not higher than the end pressure permissible for the regulator.

Safety devices are diverted to prevent pressure increases above a given value and prevent the movement of the medium in the direction opposite. As safety reinforcement Reverse, shut-off, reset, speed valves are used.

Safety shut-off valves (PZK) are used to automatically stop supplying gas to consumers in the event of a change in its pressure at a controlled point over the specified limits. They are installed in GRP (GRU), on gas wiring, in front of the burners of the high-consuming aggregates.

The accuracy of the PZC operation should be ± 5% of the specified controlled pressure values \u200b\u200bfor the PZK installed in the hydraulic fracture, and ± 10% for the PPC in the CRP cabinets (GRU). Basically for GRP (GRU) and large gas-consuming units, safety lock valves of PKV and PCN with the diameters of the conditional passage 50, 80, 100 and 200 mm are used. In the PKV valve membrane, a tougher spring was applied, which makes it possible to use it on high pressure gas pipelines.

Safety-shut-off valve type PKN (B) (Fig. 4.3.) Consists of a cast-iron cast body 1 of the valve type, a membrane chamber, a superscript head and leverage systems. Inside the case there is a saddle and a valve 9. The valve stem is included in the connection with the lever 14, one end of which is mounted hinged inside the case, and the other with the car is removed. To open the valve 9 using the lever 14, the rod rises slightly slightly and is held in this position, while the hole in the valve and the pressure drop is reduced before and after it decreases. The lever with a load 14 is introduced into engage with anchor lever 15, which is fixed on the hinge body. Impact hammer 17 is also fastened to be hinged and located above the shoulder of the anchor lever. A membrane chamber is located above the housing under the superstructure head, in which gas is supplied under the membrane from the work gas pipeline. On the membrane from above there is a rod with a socket, into which one shoulder includes a rocker 16. The other shoulder of the rocker is in engaging with the shock hammer pin.

Fig.4.3. Safety-shut-off valve type PKN (B):

Safety discharge valves.

Safety dumping valves are triggered by increasing the operating pressure to + 15%, the gas reset method into the atmosphere.

As one of the types pipe fittings safety valve (Fig.4.4) Designed for automatic protection technological system and pipelines from an invalid increase in the pressure of the work environment. Split spring and lever safety valves.

According to the method of outputting the working environment, a valve is separated by a safety, working without backpressure and discounting the working environment into the atmosphere, and the valve safety with a back pressure dropping the working environment into the pipeline.

Fig. 4.4. Safety-lock valves PCN (PKV):

1 - fitting, 2.4 - levers, 3, 10 - chiffs, 5 - nut, 6 - plate, 7.8 - springs, 9 - drummer, 11 - rocker, 12 - membrane

Also, the valve safety spring can be equipped with a manual undermining lever for checking its performance or manual production of the working medium.

The valve is safety (dumping valve) are designed to protect equipment from unacceptable pressure over the installed. Safety valves are used on tanks, boilers, tanks, vessels and pipelines for automatic or manual pressure reset into the atmosphere or reproductive pipeline. After reducing the pressure to the desired limit, the safety valve stops resetting the environment. Safety valves Designed for liquid and gaseous, chemical or oil workers. Norms of tightness according to GOST 9789-75.

In the explanatory note to the project, you need to specify the limits of the operation of the PPC and PSK, but what are the rules to refer when specifying these limits?

You must specify these data:

PZK - 1.25 operating pressure. For example: at operating pressure of 0.3, the limit of the PZK \u003d 0.3 * 1.25 \u003d 0.375

PSK - 1.15 of the operating pressure. For example: at operating pressure of 0.3, the limit of the PZK \u003d 0.3 * 1.15 \u003d 0.345

According to PB 12-529-03 "Safety rules of gas distribution systems and gas consumption":

2.4.21. Preparation accuracy of safety shut-off valves (PZK) should be ± 5% of the specified values \u200b\u200bof the controlled pressure for the PZC installed in the GPP, and ± 10% for PPCs in the CPP cabinets, gru and combined controls.

2.4.22. Safety dumping valves (PSK) must provide a discovery when an established maximum working pressure is exceeded by no more than 15%.

The pressure at which the valve is complete occurs, is set by the appropriate standard or technical Conditions on the manufacture of valves.

Spring PCCs must be equipped with a device for their forced opening.

At low pressure gas pipelines, it is allowed to install a PSK without fixture for forced opening.

The document is replaced by:

Federal standards and rules in the field industrial safety "Safety rules for gas distribution and gas consumption." In these norms, there is nothing about the limits of the triggering of the PZC and PSK.

Found suitable items here:

5.18 To stop supplying gas to consumers with an invalid increase or decrease in gas pressure behind the regulatory device, PZK applies different designs (lever, spring, with salt-shaped drive, etc.) that are responsible for the following requirements:

PZK is calculated on the inlet operating pressure, MPa, for a number: 0.05; 0.3; 0.6; 1.2; 1.6 with a response range when pressure rises, MPa, from 0.002 to 0.75, as well as with a response range with a decrease in pressure, MPa, from 0.0003 to 0.03;

The design of the PZC should exclude spontaneous opening of the locking body without the intervention of the service personnel;

The tightness of the shut-off authority PZC must comply with the class "A" according to GOST 9544;

The accuracy of the operation should be, as a rule, + -5% of the specified values \u200b\u200bof the controlled pressure for the PZC installed in the hydraulic and + -10% for the PSC in the SCR and GRU.

5.19 To reset the gas behind the regulator in the case of a short-term increase in gas pressure over the installed, safety dumping valves (PSK), which may be membrane and spring should be applied.

5.20 Spring PCs should be equipped with a device for their forced opening. Shrp bandwidth up to 100 m3 / h, equipped with a two-stage regulator, is allowed not to equip PSK.

5.21 PSK should provide discovery when increasing the installed maximum working pressure by no more than 15%.

5.22 PSK should be calculated on the input working pressure, MPa, for a number: from 0.001 to 1.6 with a response range, MPa, from 0.001 to 1.6.

8.1.5 The settings for adjusting the reduction reinforcement of gas reduction points should be determined taking into account the loss of gas pressure in the distribution gas pipelines, the operating pressure range in front of the gas-propying equipment of consumers, gas pressure fluctuations in the gas distribution network due to uneven gas consumption.

With the gas pressure in the distribution gas pipeline at the output from the gas reduction points to 0.005 MPa, the parameters of the reduction reinforcement should provide the following parameters of the gas pressure in front of the consumer's household gas-

At rated pressure of household gas-grade equipment 0.0013 MPa - no more than 0.002 MPa;

At rated pressure of household gas-grade equipment 0.002 MPa - no more than 0.003 MPa.

8.1.6 Settings (triggering) Safety and protective reinforcement must provide protection for gas pipelines and equipment located below flow gas, from an invalid pressure change as well safe work Gas-grade consumer equipment in the pressure range established by manufacturers.

8.1.7 Upper protective reinforcement setting limit ( Predelectrics Z.aprony TOlapanov) should not exceed:

1.3 p - with a gas pressure in the gas pipeline at the output from the gas reduction points ranging from 0.3 to 1.2 MPa;

1.4 p - at a gas pressure in the gas pipeline at the output from the gas reduction points ranging from 0.005 to 0.3 MPa;

1.5 p - with a gas pressure in the gas pipeline at the output from the gas reduction points below 0.005 MPa,

For high and medium pressure gas pipelines - maximum overpressure gas for this category of gas pipeline installed;

For low pressure gas pipelines - the maximum overpressure of the gas adopted in accordance with 8.1.5 (0.002 or 0.003 MPa).

8.1.8 Setting the safety reinforcement ( Predelectrics FROMchallenges TOlapanov) gas pipelines of all pressures should not allow gas discharge into the atmosphere while increasing the pressure in the gas pipeline due to the structural characteristics of pressure regulators, including with a small flow rate or the absence of gas flow (work on a dead end).

The pressure on the opening of the safety reinforcement for gas pipelines of medium and high pressures should be at least 5% higher than the pressure adopted for this type of gas pipeline.

For low pressure gas pipelines, the opening of the safety reinforcement should be installed by 0.0005 MPa above the pressure adopted in accordance with 8.1.5.

One of the options to write like this:

According to GOST R 54983-2012, the trigger limits of the PSK, with an increase in the output pressure to 0.0025MP (P + 0.0005MPA), and the limits of the PSC response, with an increase in the output pressure of 0.003 MPa (1.5P).

If you know a more accurate answer to this question, please write.

Topics discussion on forums: