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All manufactured products have Rostekhnadzor permits for use, technical passports, manufacturing certificates, operation manuals and certificates of conformity. Additional parameters, such as: product weight, overall dimensions, drawing, are sent upon request.
The valve is distinguished by a variety of designs, which depends on the functional purpose of the valve. Basically, valves are divided into shut-off, control, safety and check valves. Bypass, breathing, shut-off, shut-off, reducing, mixing and distributing, balancing valves are less common. Let's consider some of them:
- A bypass valve is a device designed to maintain the pressure of a liquid or gaseous medium at a given level by bypassing it through a pipeline branch. Unlike a safety valve, a bypass valve provides a continuous removal of the medium from the system. It should be noted that this type of valve maintains a constant pressure at the inlet to the valve, that is, “up to itself”;
- The breathing valve is designed to minimize the loss of oil products during the breathing of the tank while preventing it from exceeding the specified values of pressure and vacuum;
- The shut-off valve is a protective fitting necessary to prevent leakage or release of the working medium in the event of a pipeline rupture. In addition, they significantly limit the flow of the medium in the system in excess of the established limit. Basically, shut-off valves are used on pipelines of small diameter when transporting media that leak into environment unacceptable;
- The shut-off valve is used to quickly shut off the pipeline in emergency situations or according to technological necessity. Such a valve comes into action by means of a pneumatic or electric drive on command from special sensors;
- The pressure reducing valve is an automatically operated throttle that maintains a constant outlet pressure. It can be used both to reduce pressure and to equalize variable pressure;
- A mixing valve is a type of control valve that is used to mix several medium streams into one in order to stabilize the properties of the working medium. The mixing valve body is characterized by the presence of two inlets and one outlet. It should be noted that only the ratio of flows changes during the mixing process, while the flow rate always remains unchanged;
- The distribution valve is designed to direct the flow of the working medium from two or more pipelines into one. Often, a control valve is used to control pneumatic and hydraulic actuators. Depending on the number of lines served, this valve is divided into three-way, four-way and multi-way valves;
- A balancing valve is a type of throttling valve designed to ensure the calculated flow distribution over the elements of the pipeline network or the stabilization of circulation pressures or temperatures in them. Balancing valves divided into manual and automatic.
Climatic version - these are the climatic conditions for the operation of valves, which are determined in accordance with GOST 15150-69.
The type of flange connection according to execution and the material of the gasket are selected depending on the operating conditions of the valve, pressure, operating temperature and corrosive properties of the medium.
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Pipe fittings with drive control used in cases of frequent use pipe fittings. It is also used when it is necessary to quickly act on the working body of the reinforcement in hazardous conditions and in emergency situations.
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Pipeline or shutoff valves - technical devices, which are installed on pipelines and containers. Depending on the working environment and its parameters, pipeline fittings are divided into steam-water fittings: for steam pipelines and water supply systems; power fittings, oil, gas, sewer, ventilation, cryogenic, vacuum, reservoir. Plumbing systems are engineering structures that solve the problems of water supply to various consumers. Distinguish between internal and external plumbing systems. Power fittings - used on steam and water pipelines of power equipment and installations, power units, thermal power plants and nuclear power plants. Power fittings provide start-ups and shutdowns of power equipment, load shedding and loading, regulation of the flow and pressure of the working medium, protection against overpressure and reverse flows of the medium. For these purposes, the following pipeline fittings are used: control, protective, safety and stop valves. Among the power fittings, the most widespread are special shut-off valves DN from 6 to 65 mm: air, three-way, shut-off valves, gate valves with a small-sized gate. Air valves DN 6 mm are used to release steam or air from pipelines or boilers during the kindling period. To connect pressure gauges, three-way valves DN 10 mm are used. Among the most used stop valves on power equipment - shut-off valves DN from 10 to 65 mm, operating on steam and water. Gate valves are used as controlled shut-off devices for shutting off the medium in the main steam and water lines. For these purposes, gate valves with DN 100 - 450 mm are used.
Carbon steel is one of the most common material groups for the production of pipeline components. It is designed for products transporting neutral, slightly aggressive liquid and gaseous media at threshold temperatures from -40 to +425 degrees. Exact values allowable temperature transported substances is calculated separately for each steel grade of this type.
The slam-shut safety shut-off valve is set to actuate when pressure outlet of the conducted medium maximum or minimum set value. Setting range specified in the user manual for the product.Device required
included in the equipment kit gas distribution points, to stop the gas supply to the consumer's system in case of deviation operating pressure from established values andprotection regulators, pressure gauges, counterov and other operated gas appliances. Wherein resume gas supply can only be operated by service personnel, having previously eliminated the cause that caused valve actuation and interruption of gas supply to consumers.When the gas pressure on the burners of the appliances rises above the permissible limit, flame separation may occur. , which will entail gas flow into the room or working chambers and furnace spaces of installations , creating conditions under which there is a risk of explosion. To prevent such situations, a PZK valve is used, which cuts off the gas supply in the event of a critical increase in pressure. The design of the product also provides for operation in the event of an equally dangerous, significant decrease in operating pressure, since this may cause roskok flame in the nozzles of the burners, which will lead to incomplete combustion of gas and may end destruction eat the burners themselves if burning gas continue inside them and will not be terminated immediately.
To ensure the normal operation of the product, it is necessary install directly before the regulators along the gas flow. In this case, the maximum set pressure to be configured depends on the value of the maximum allowable pressure for used gas networks. The minimum set pressure is determined by the pressure below which there is a risk of interruption in operation of gas appliances and installations. reasons oh unacceptable increase or decrease in gas pressure after the regulator for dead-end networks may be: a malfunction of the pressure regulator (jamming of the plunger, the formation of hydrate plugs in the seat and body, leakage of the shutter); improper selection of the regulator according to its throughput, leading to a two-position mode of its operation at low gas flow rates and causing outbursts of output pressure and self-oscillations.The reason for the unacceptable increase or decrease in gas pressure after the regulator for ring and branched networks may be: a malfunction of one or more pressure regulators supplying these networks; incorrect hydraulic calculation of the network, due to which abrupt changes in gas consumption by large consumers lead to surges in outlet pressure.
A common cause of a sharp decrease in pressure for any network may be a violation of the tightness of gas pipelines and fittings, and, consequently, a gas leak.
After switching on gas distribution point to work, check the tightness of the connections soapy water and any leaks found should be repaired immediately.
Safety shut-off valve must be set up so as to operate at several more pressure, how relief valve . However, its value should not be higher than the maximum allowable working gas pressure, at which the normal operation of gas burners is ensured. Checking the product for setting accuracy and operation is carried out as follows: it is necessary to gradually povy up or down pressure while watching At what pressure will the valve open? If the pressure is correct, the valve setting is left unchanged. Otherwise, you need to make adjustments. When checking the valve, gas must be supplied through the bypass line.The adjustment is carried out to a pressure that exceeds the final pressure (behind the regulator) at the point of impulse sampling by 25 - 50%, but not higher than the permissible pressure for the final pressure regulator.Safety shut-off valves PZK designed to automatically stop the gas supply to the consumer when the controlled gas pressure rises or falls relative to the set values. The working medium is natural gas according to GOST 5542-2014.
Issued by TU 3712-021-12213528-2011
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LLC PKF EX-FORMA is a developer ohm and manufacturer of safety shut-off valves PZK with nominal diameters of 50, 100 and 200 mm. PZK safety shut-off valves are designed for tight shut-off of gas pipelines in case of gas pressure going beyond controlled limits. The use of a membrane with a large active area and a minimum number of rubbing parts in the shut-off valve increases the accuracy and reliability of operation. PZK valves automatically close when the controlled pressure goes beyond the set upper and lower limits. The shut-off valves are opened manually. Arbitrary opening of valves is excluded. The service life of the slam-shut valve is at least 30 years, 3 years warranty, Overhaul interval - 7 years. |
PZK valves automatically close when the controlled pressure goes beyond the set upper and lower limits. The opening is done manually. Arbitrary opening of valves is excluded.
The valves are produced in two pressure versions - with low or high outlet pressure, in three versions according to the nominal bore - DN 50, DN 100, DN 200 and in two versions according to the location of the cocking handle - right or left.
The right version of the Valve is considered to be such a version, in which the cocking handle is located on the right, if you look at the inlet flange of the Valve along the gas flow.
The location of the cocking handle on the left is considered to be the left version of the Valve.
Advantages of the slam shut valve:
- fundamentally new design device and the absence of external actuators exclude false positives valve;- the design of the device eliminates the displacement of the working valve relative to the seat;
- the minimum number of rubbing parts of the ball valve increases the accuracy and reliability of work;
- the design of the locking mechanism has been successfully tested for several years in the shut-off valve of the RDK regulator.
Technical characteristics of slam-shut valves
| Parameter name | PZK-50N | PZK-50V | PZK-100N | PZK-100V | PZK-200N | PZK-200V |
| Working environment |
Natural gas GOST 5542-2014 |
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Nominal passage, DN, mm |
50 | 50 | 100 | 100 | 200 | 200 |
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Maximum inlet pressure, MPa |
1,2 | 1,2 | 1,2 | 1,2 | 0,6/1,2 | 0,6/1,2 |
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Controlled pressure setting limits: - at pressure decrease, Kpa - with increasing pressure, Kpa |
0,4-3 |
3-30 |
0,4-3 |
3-30 |
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| Actuation accuracy, %, no more | 2 | 5 | 2 | 5 | 2 | 5 |
| Tightness class | "A" according to GOST 9544-2015 | |||||
| Construction length, mm | 230±1.5 | 230±1.5 | 350±2 | 350±2 | 600±2 | 600±2 |
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dimensions, no more: - length, mm - width, mm - height, mm |
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| Gas connection |
Flanged according to GOST 33259-2015 |
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| Weight, kg, no more | 19 | 19 | 30 | 30 | 141 | 141 |
Advantages of slam shut valve
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Production |
Exploitation |
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Cast aluminum housing Body parts are made in our own foundry from cast aluminum grades. |
False positives excluded A fundamentally new design of the device and the absence of external actuators exclude false actuation of the valve |
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Membrane sheet EFFBE The French EFFBE membrane fabric provides high elasticity and retains its original properties in temperature regime from -40°С to + 60°С. |
High degree of reliability The valve actuation accuracy is within 1-2% of the preset settings for high pressure gas and 5% for low pressure. |
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Ball valve design A fundamentally new ball valve design with the minimum amount rubbing parts increases the accuracy and reliability of work. |
Arbitrary opening of the valve is excluded The design of the valve excludes spontaneous opening in case of operation. Restart is only possible manually. |
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Wurth sabesto lubricant The sliding mechanism of the slam-shut valve uses wurth sabesto grease, which ensures the operation of the regulator both at high and low temperatures. |
Response time less than 1 second The tight closing time of the valve is less than 1 second when the pressure is increased or decreased. The cocking of the valve is made by simple turn of the handle. |
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Quality control Before shipment to the customer, each valve is tested for performance under conditions that simulate real operating conditions. |
Displacement of the working valve is excluded The design of the device eliminates the displacement of the working valve relative to the seat, which allows you to maintain the tightness of the Class A shutter for the entire service life. |
PZK valve device
The valve has a flanged body of valve type pos.1. Inside the body there is a seat, which is closed by a valve pos.2 with a rubber seal. The valve hangs freely on the stem pos.3, which moves in the guides of the hub pos.4 and the separator pos.5 installed in the head pos.6.
The stem is also a bypass valve, which serves to equalize the pressure before and after the valve before opening it.
The opening of the valve is made by the handle pos.7, put on the axis pos.8 with the fork pos.9 mounted on it.
Closing of the valve is carried out by a spring pos.10.
The internal cavity of the head forms a submembrane cavity of controlled pressure.
The movable system of the membrane type pos.11 is attached between the head and the cover pos.12. In the central part of the movable system, a carriage pos.13 is mounted, which, with the help of balls pos.14, installed in the separator, locks the rod when it is cocked.
A controlled pressure adjustment mechanism is placed inside the lid. Pin poz.15 with stop poz.16 abuts against the carriage of the movable system. A washer poz.17 is put on the stop, which rests on the protrusions of the cover glass poz.18. Between the stop and the adjusting screw pos.19, a small spring pos.20 is installed, which determines the setting for lowering the controlled pressure, the gain is adjusted by turning the adjusting screw pos.19.
On the washer poz.17 the lower end is supported by the spring poz.21, which determines the setting for increasing the controlled pressure, the spring force is changed by rotating the adjusting cup poz.22. Controlled pressure is applied under the diaphragm through a nipple.
The principle of operation of the slam-shut valve
The platoon of the Valve is made by turning the handle pos.7, on the same axis with which the fork is attached. As a result of the axial movement of the stem, the bypass valve opens and the pressure in the body cavities equalizes. This makes it possible to open the main valve.
At a given output pressure, the membrane, together with the carriage pos.13, occupies a neutral position. The collar of the carriage keeps the balls pos.14 from radial movement. The collar of the rod pos.3 abuts against the balls, blocking the axial movement of the rod. Spring poz.21 with its lower end through the washer rests against the protrusions of the cover glass and does not exert pressure on the membrane.
The stop poz.16 is adjusted on the pin poz.15 in such a way that when the membrane is in the neutral position it is in contact with the washer poz.17, and the pin with the membrane carriage.
When the output pressure is increased or decreased to the values of the triggering setting, the membrane moves (respectively upwards under the action of pressure or downwards under the action of the spring poz.20) together with the carriage poz.13. The balls move in the radial direction, releasing the stem. Under the influence of the spring pos.10, the valve pos.2 is pressed against the seat, shutting off the gas flow.
Preparing the slam-shut valve for operation
The valve must not be installed in environments that are corrosive to cast iron, aluminium, steel, rubber and zinc coating. The valve is mounted on a horizontal section of the pipeline in front of the pressure regulator. The membrane must be in a horizontal position. The gas inlet must correspond to the arrow molded on the body.
The impulse tube must be connected to the nipple (welded) and, if possible, slope down from the head and not have areas with the opposite direction of the slope, in which condensate can accumulate.
Connection of a tube to the lower quarter of a horizontal pipeline in which pressure is controlled is not allowed. The impulse is taken after the pressure regulator. Check the quality of the installation by testing for tightness at operating pressure with the application of a soapy emulsion at the joints. Leaks are not allowed.
The procedure for setting and operating the slam-shut valve
Upon completion of installation and pressure testing of the valve, it is necessary to adjust the operating parameters.
Safety devices are designed to prevent pressure increase above the set value and to prevent the movement of the medium in the opposite direction to the set value. Check, shut-off, relief, high-speed valves are used as safety fittings.
Safety shut-off valves(PZK) are used to automatically stop the supply of gas to consumers in the event of a change in its pressure at a controlled point in excess of the specified limits. They are installed in the GRP (GRU), on gas wiring, in front of the burners of gas-consuming units.
The accuracy of the slam-shut valve operation should be ±5% of the specified controlled pressure values for the slam-shut valve installed in the hydraulic distribution unit, and ±10% for the slam-shut valve in the cabinet-type hydraulic distribution unit (GRU). Basically, for hydraulic fracturing (GRU) and large gas-consuming units, safety shut-off valves PKV and PKN with nominal diameters of 50, 80, 100 and 200 mm are used. A more rigid spring is used in the PKV valve membrane, which allows it to be used 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 superstructure head and a system of levers. Inside the body there is a seat and a valve 9. The valve stem is connected to the lever 14, one end of which is hinged inside the body, and the other with the load is brought out. To open the valve 9 with the help of the lever 14, the stem is first slightly raised and held in this position, while opening the hole in the valve and the pressure drop before and after it decreases. The lever with the load 14 is engaged with the anchor lever 15, which is pivotally mounted on the body. Impact hammer 17 is also hinged and located above the arm of the anchor lever. A membrane chamber is located above the body under the superstructure head, into which gas is supplied from the working gas pipeline under the membrane. On the top of the membrane there is a rod with a socket, into which the rocker arm 16 enters with one arm. The other arm of the rocker engages with the hammer pin.
Fig.4.3. Safety shut-off valve type PKN (B):
Safety relief valves.
Safety relief valves are triggered when the operating pressure rises up to +15%, by releasing gas into the atmosphere.
As one of the types of pipeline fittings safety valve(Fig.4.4) is designed to automatically protect the process system and pipelines from an unacceptable increase in pressure of the working medium. There are spring and lever safety valves.
According to the method of release of the working medium, a safety valve is divided, which operates without backpressure and discharges the working medium into the atmosphere, and a safety valve with counterpressure, which discharges the working medium into the pipeline.
Rice. 4.4. Safety shut-off valves PKN (PKV):
1 - fitting, 2.4 - levers, 3, 10 - shifts, 5 - nut, 6 - plate, 7.8 - springs, 9 - drummer, 11 - rocker, 12 - membrane
Also, the safety spring valve can be equipped with a manual lifting lever to check its performance or manual release of the working medium.
The safety valve (relief valve) is designed to protect equipment from unacceptable excess pressure in excess of the set pressure. Safety valves are used on tanks, boilers, containers, vessels and pipelines for automatic or manual release of pressure into the atmosphere or discharge pipeline. After reducing the pressure to the desired limit, the safety valve stops the discharge of the medium. Safety valves are intended for liquid and gaseous, chemical or oil working environments. Tightness standards according to GOST 9789-75.
Increasing or decreasing the gas pressure after the pressure regulator in excess of the specified limits can lead to emergency. With an excessive increase in gas pressure, flame separation from the burners and the appearance of an explosive mixture in the working volume of gas-using equipment, leakage, gas leakage in the joints of gas pipelines and fittings, failure of instrumentation, etc. are possible. A significant decrease in gas pressure can lead to slippage of the flame into the burner or extinction of the flame, which, if the gas supply is not turned off, will cause the formation of an explosive gas-air mixture in the furnaces and gas ducts of the units and in the premises of gasified buildings.
The reasons for the unacceptable increase or decrease in gas pressure after the pressure regulator for dead-end networks are:
Malfunction of the pressure regulator (jamming of the plunger, the formation of hydrate plugs in the seat and body, valve leakage, etc.);
incorrect selection of the pressure regulator according to its throughput, leading to a two-position mode of its operation at low gas flow rates and causing outbursts of outlet pressure and self-oscillations.
For ring and branched networks, the reasons for an unacceptable pressure change after the pressure regulator can be:
Malfunction of one or more pressure regulators supplying these networks;
incorrect hydraulic calculation of the network, due to which abrupt changes in gas consumption by large consumers lead to surges in outlet pressure.
A common cause of a sharp decrease in pressure for any network may be a violation of the tightness of gas pipelines and fittings, and, consequently, a gas leak.
To prevent an unacceptable increase or decrease in pressure in the hydraulic fracturing (GRPSh), high-speed safety shut-off valves (PZK) and safety relief valves (PSK) are installed.
PZK are intended for automatic stop of gas supply to consumers in case of increase or decrease in pressure over the set limits; they are installed after the pressure regulators. PZK work at "emergency situations", therefore their spontaneous inclusion is inadmissible. Before manually turning on the slam-shut device, it is necessary to detect and eliminate malfunctions, and also make sure that the shut-off devices in front of all gas-using devices and units are closed. If, according to the conditions of production, a break in the gas supply is unacceptable, then instead of a shut-off valve, an alarm system should be provided to alert the maintenance personnel.
PSK are designed to discharge into the atmosphere a certain excess volume of gas from the gas pipeline after the pressure regulator in order to prevent pressure from rising above the set value; they are installed after the pressure regulator on the outlet pipeline.
In the presence of a flow meter (gas meter), PSK must be installed after the meter. For GRPSh, it is allowed to take out the PSK outside the cabinet. After reducing the controlled pressure to a predetermined value, the PSK must be hermetically sealed.
Safety shut-off valves
PZK is a valve open in operational condition. The flow of gas through it stops as soon as the pressure at the controlled point of the gas pipeline reaches the lower or upper limit of the slam-shut setting.
The following requirements are imposed on the PZK:
It must ensure hermetic closure of the gas supply to the regulator in the event of an increase or decrease in pressure behind it in excess of the established limits. The upper limit of the shut-off valve operation should not exceed the maximum working pressure after the regulator by more than 25%;
calculated for the inlet working pressure in the series: 0.05; 0.3; 0.6; 1.2; 1.6 MPa with a response range when pressure increases from 0.002 to 0.75 MPa, as well as a response range when pressure decreases from 0.0003 to 0.03 MPa;
the design should exclude spontaneous opening of the shut-off body without the intervention of maintenance personnel;
the tightness of the shut-off body must comply with class "A" in accordance with GOST 9544-93;
response accuracy should be ± 5% of the set values of controlled pressure for slam-shut valves installed in hydraulic fracturing, and ± 10% for slam-shut valves in GRPSh and combined regulators;
response inertia should be no more than 40–60 s;
the free passage of the shut-off body must be at least 80% of the nominal passage of the slam-shut pipes;
the shut-off body should not be at the same time the executive body of the gas pressure regulator.
The sampling of the pulse of the controlled pressure of the SVK must be done near the point of sampling of the pulse of the pressure regulator, i.e. at a distance from the pressure regulator of at least five diameters of the outlet gas pipeline. Connect the slam-shut impulse piping to the bottom horizontal section gas pipeline is unacceptable to prevent the ingress of condensate.
Slam-shut valves installed in hydraulic fracturing and on-site hydraulic fracturing are often used as actuators security automation, stopping the gas supply when any of the controlled parameters deviates beyond the specified limits (including at the command of the gas contamination detector). In this case, the PZK is usually equipped with an electromagnetic device. The PZK also includes thermal shut-off valves that shut off pipelines in the event of a temperature rise to 80–90 ° C.
