Safety relief valves psk. Safety relief valve psk Safety relief valve psk 50 passport
Characteristics
Description
| Name of parameter or size | Magnitude |
|---|---|
| 1 Nominal diameter, mm | 50 |
| 2 Maximum valve opening pressure, kPa (kgf/cm 2) | |
| PSK-50N/5 | 5(0,05) |
| PSK-50S/20 | 20(0,2) |
| PSK-50S/50 | 50(0,5) |
| PSK-50S/125 | 125(1,25) |
| PSK-50V/400 | 400 (4) |
| PSK-50V/700 | 700 (7) |
| 3 Response setting range, kPa | |
| PSK-50N/5 | from 2 to 5 |
| PSK-50S/20 | from 5 to 20 |
| PSK-50S/50 | from 20 to 50 |
| PSK-50S/125 | from 50 to 125 |
| PSK-50V/400 | from 125 to 400 |
| PSK-50V/700 | from 400 to 700 |
| 4 Valve tightness class | B according to GOST 9544-2005 |
| 5 Connection dimensions: at the inlet and outlet, internal pipe thread according to GOST 6357-81, inches | 2 |
| 6 Overall dimensions, mm, no more | |
| - diameter | 220 |
| - height | 255 |
| 7 Weight, kg, no more | 5,0 |
Note: The safety relief valve setting should be 1.15 working pressure.
Average service life, years, not less than 15;
Designated service life, years, not less than 40.
Purpose of the product
Safety relief valves PSK are designed to limit the pressure of non-aggressive gases by releasing the gas into the atmosphere to a set value when the pressure in the network increases above the permissible limit.
The valves are installed on gas pipelines of low, medium and high pressure, as well as at regulatory stations.
The operating conditions of the valves correspond to the climatic version UHL2 GOST 15150-69 with an ambient temperature from minus 40 to plus 60° C.
Valves during operation do not have a negative impact on environment.
Design and principle of operation
The safety relief valve PSK-50 consists of a body 1 (see Figure 1), a cover 2, a valve 3 with a guide and rubber seal, spring 4 and adjusting screw 5, membrane 6, plate 7 and spring plate 8.
Housing 1 is made in the form of a truncated cone, with a flange, a seat and two holes with a 2" thread. The seat is closed by valve 3 with a rubber seal. The valve is assembled with a membrane 6, which is fixed between the body flange and the cover 2.
Spring 4 is clamped between the membrane plates and the adjusting screw 5. By rotating the adjusting screw, the spring plate 8 moves, thus changing the force of the spring, which determines the valve response pressure setting.
Gas from the network enters the supravalvular cavity through the inlet of the housing.
In steady state, the controlled gas pressure within the established limits is balanced by the adjusted spring and the valve is hermetically closed.
When the gas pressure in the network (above the valve) exceeds the setting limit, the valve, overcoming the spring force, opens, allowing gas to escape into the atmosphere.
The gas discharge will continue until the pressure in the network drops below the set value, after which the valve will close under the action of the spring.
1- body; 2 – cover; 3 – valve with guide and rubber seal; 4 – spring; 5 – adjusting screw;
6 – membrane; 7 – plate; 8 – spring plate.
Figure 1. Safety relief valve PSK-50N
1– body; 2 – cover; 3 – valve with guide and rubber seal; 4 – spring; 5 – adjusting screw; 6 – membrane; 7 – plate; 8 – spring plate.
Figure 2. Safety relief valve PSK-50V
To relieve gas downstream of the regulator in the event of a short-term increase in gas pressure above the set value, safety relief valves (PSVs) must be used. PSK is a valve that is closed in operational condition; it opens for a short period of time, and after the pressure at the controlled point reaches the nominal value, it automatically closes.
PSC can be spring or membrane. Spring-loaded valves must be equipped with a device for their forced opening and control purging in order to prevent sticking, freezing and sticking of the spool to the seat, as well as to remove solid particles trapped between the sealing surfaces.
PSKs are divided into full-lift and low-lift. For low-lift valves (PSK type), the valve opens gradually, in proportion to the increase in pressure at the controlled point of the gas pipeline. Full-lift valves (SPPKR4R-16) open completely and sharply, with a jerk, and just as sharply, with the spool hitting the seat, they close when the pressure decreases. That is, a full-lift valve has a two-position position: “closed” and “open”.
When the maximum permissible setting pressure is reached, the PSK valve must open without fail to full lift and operate stably in the open position. The valve must close when the pressure drops to the nominal pressure or below it by 5% and ensure tightness. If there is a delay in closing the valve, the gas pressure in the network may drop significantly, which can lead to disruption of the system’s operating mode, as well as the release of relatively large quantity gas
For low-lift PSKs, when closing the shutter after resetting required quantity gas, it is difficult to achieve tightness of the shutter, since this may require applying more force than in the “closed” mode.
Such PSCs stop releasing gas only after the pressure decreases to 0.8-0.85% of the operating pressure, which leads to a constant or long-term release of gas into the atmosphere. The main advantage of membrane PSCs is the presence in their design of an elastic membrane that acts as a sensitive element. If in spring valves The spool performs the functions of both a sensing element and a shut-off element, while in diaphragm valves the spool performs only shut-off functions. The membrane makes it possible to increase the sensitivity of PSCs in general and expand the range of their use, including low gas pressure. PSCs must ensure opening when the established operating pressure is exceeded by no more than 15%.
The choice of UCS design should be made in accordance with the throughput.
The amount of gas to be discharged by the PSK should be determined:
- if there is a SCP in front of the pressure regulator according to the formula Q≥0.0005Q d, where Q is the amount of gas to be discharged by the SCP within an hour at t = 0 °C and P bar = 0.10132 MPa, m 3 / h; Q d - design capacity of the pressure regulator at t = 0 °C and P bar = 0.10132 MPa, m 3 / h;
- in the absence of a slam-shut valve in front of the pressure regulator according to the formulas: for pressure regulators with a seat valve - Q≥0.01Q d, for control valves - Q≥0.02Q d.
Low-lift membrane and spring PSKs have a small throughput. Thus, the throughput capacity of SPPK4R-50-16 (seat diameter 30 mm) at an operating pressure of 0.125 MPa is 830 m3/h, and PSK-50S/125 (seat diameter 50 mm) is only 10 m3/h. This is explained by the low lifting height of the spool. Bandwidth valves PSK-50 (KPS-50) with guide fins at low pressure is: 0.5-3 m3/h, at average - 7-20 m3/h (at a pressure in the PSK inlet pipe of 1.15 setting pressure).
The throughput capacity of PSK-50 without guide ribs with the same parameters can be assumed to be twice as large.
The table (page 1245) shows the main technical specifications serially produced PSK. In addition to these PSCs, relief valves can also be part of ( constituent element) combined gas pressure regulators.
To relieve gas downstream of the regulator in the event of a short-term increase in gas pressure above the set value, safety relief valves (PSVs) must be used.
PSK is a valve that is closed in operational condition; it opens for a short period of time, and after reaching the nominal pressure at the controlled point, it automatically closes.
PSC can be spring or membrane. Spring-loaded valves must be equipped with a device for their forced opening and control purging in order to prevent sticking, freezing and sticking of the spool to the seat, as well as to remove solid particles trapped between the sealing surfaces.
PSKs are divided into full-lift and low-lift. For low-lift valves (PSK type), the valve opens gradually, in proportion to the increase in pressure at the controlled point of the gas pipeline. Full-lift valves (SPPKR4R-16) open completely and sharply, with a jerk, and just as sharply, with the spool hitting the seat, they close when the pressure decreases. That is, the full-lift valve has a two-position position: closed and open.
When the maximum permissible setting pressure is reached, the PSK valve must open without fail until it is fully raised, and operate stably in the open position. The valve must close when the pressure drops to the nominal pressure or below it by 5% and ensure tightness. If there is a delay in closing the valve, the gas pressure in the network may drop significantly, which can lead to disruption of the system’s operating mode, as well as the release of a relatively large amount of gas into the atmosphere.
For low-lift PSKs, when closing the valve after releasing the required amount of gas, it is difficult to achieve sealing of the valve, since for this it is sometimes necessary to apply a force greater than in the “closed” mode. Such PSCs stop releasing gas only after the pressure decreases to 0.8–0.85% of the operating pressure, which leads to a constant or long-term release of gas into the atmosphere. The main advantage of membrane PSCs is the presence in their design of an elastic membrane that acts as a sensitive element. If in spring valves the spool performs the functions of both a sensing element and a shut-off element, then in diaphragm valves the spool performs only shut-off functions. The membrane makes it possible to increase the sensitivity of PSCs in general and expand the range of their use, including low gas pressure. PSK must ensure opening when the established operating pressure is exceeded by no more than 15%.
The choice of UCS design should be made in accordance with the throughput.
The amount of gas to be discharged by the PSK should be determined:
If there is a SCP in front of the pressure regulator according to the formula Q≥0.0005Qd, where Q is the amount of gas to be discharged by the SCP within an hour at t=0° C and Pbar=0.10132 MPa, m³/h; Qd - design capacity of the pressure regulator at t=0° C and Pbar=0.10132 MPa, m³/h;
in the absence of a slam-shut valve in front of the pressure regulator according to the formulas: for pressure regulators with a seat valve Q≥0.01Qd, for control valves Q≥0.02Qd.
Low-lift membrane and spring PSKs have a small throughput. Thus, the throughput capacity of SPPK4R-50-16 (seat diameter 30 mm) at an operating pressure of 0.125 MPa is 830 m³/h, and PSK-50S/125 (seat diameter 50 mm) is only 10 m³/h. This is explained by the low lifting height of the spool. The capacity of PSK-50 (KPS-50) valves with guide ribs at low pressure is: 0.5–3 m³/h, at average - 7–20 m³/h (at a pressure in the PSK inlet pipe of 1.15 set pressure) .
The throughput capacity of PSK-50 without guide ribs can be taken to be twice as large with the same parameters. In addition to these PSCs, relief valves can also be part (component) of combined gas pressure regulators.
Description
To limit the gas pressure using the method of releasing it into the atmosphere in cases where the permissible value is exceeded, discharge devices PSK-50 are used. The products are installed at stations and gas pipelines characterized by different pressure levels. Operating conditions refer to UHL 2GOST 15150-69, that is optimal performance provided at temperatures -40°C to +60°C.
These valves do not have negative influence on the atmosphere and environment. The service life is at least 15 years. The design consists of a body, covers with a seal, a screw, plates, springs, membranes. When the pressure changes, the valve opens, allowing gas to escape. After the process is completed, the valve returns to the closed state.
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Specifications
safety relief valve
| Name of parameter or size | Magnitude |
|---|---|
| 1 Nominal diameter, mm | 50 |
| 2 Maximum valve opening pressure, kPa (kgf/cm2) | |
| PSK-50N/5 | 5(0,05) |
| PSK-50S/20 | 20(0,2) |
| PSK-50S/50 | 50(0,5) |
| PSK-50S/125 | 125(1,25) |
| PSK-50V/400 | 400 (4) |
| PSK-50V/700 | 700 (7) |
| 3 Response setting range, kPa | |
| PSK-50N/5 | from 2 to 5 |
| PSK-50S/20 | from 5 to 20 |
| PSK-50S/50 | from 20 to 50 |
| PSK-50S/125 | from 50 to 125 |
| PSK-50V/400 | from 125 to 400 |
| PSK-50V/700 | from 400 to 700 |
| 4 Valve tightness class | B according to GOST 9544-2005 |
| 5 Connecting dimensions: at the inlet and outlet, internal pipe thread according to GOST 6357-81, inches | 2 |
| 6 Overall dimensions, mm, no more | |
| - diameter | 220 |
| - height | 255 |
| 7 Weight, kg, no more | 5,0 |
Note: The safety relief valve setting should be 1.15 working pressure.
Average service life, years, not less than 15;
Designated service life, years, not less than 40.
Safety relief valve D at 50 mm membrane type direct action installed on low, medium and high pressure gas pipelines, as well as on medium pressure hydraulic fracturing. The safety relief valve PSK-50 is manufactured in climatic version U2 GOST 15150-69, but for operation at temperatures from –10 to +35 °C.
Specifications
| PSK-50N/5 | PSK-50N/20 | PSK-50S/50 | PSK-50S/125 | PSK-50S/300 | PSK-50V/400 | PSK-50V/700 | PSK-50V/1000 | |
|---|---|---|---|---|---|---|---|---|
| Maximum working pressure, kPa (kgf/cm2) | 5 (0,05) | 20 (0,2) | 5 (0,05) | 125 (1,25) | 300 (3) | 400 (4) | 700 (7) | 1000 (10) |
| Trigger setting range, kPa | 2-5 | 5-20 | 20-50 | 50-125 | 125-300 | 125-400 | 400-700 | 125-1000 |
| Overall dimensions, mm | ||||||||
| diameter D | 225 | 225 | 225 | 225 | 225 | 230 | 225 | 230 |
| height H | 211 | 211 | 211 | 240 | 211 | 233 | 211 | 240 |
| Weight, kg, no more | 6,82 | 6,82 | 6,82 | 6,82 | 6,82 | 7,0 | 6,82 | 6,9 |
Cast iron body 1 (see figure) is made in the form of a truncated cone with a flange, a seat and two holes with 2-inch cylindrical pipe threads. The seat is closed by valve 3 with a rubber seal. The valve is assembled with a membrane 6, which is rigidly fixed between the valve 3 and the plate 7. In turn, the membrane 6 is fixed between the body 1 and the cover 2.
Spring 4 is clamped between the membrane plates 7, 8 and the adjusting screw 5. By rotating the adjusting screw 5, the lower plate 8 moves, thus changing the forces of the spring 4, which determines the setting of valve 3 to pressure within specified limits.
Depending on the version, the following are available:
- PSK-50N/5 with a low pressure spring and a washer instead of a guide;
- PSK-50S/50 with medium pressure spring;
- PSK-50S/125 with a medium pressure spring, a membrane plate reduced in diameter, and a special washer sandwiched between the body and the lid.
Gas from the network enters the supra-membrane cavity through the inlet pipe of the housing. In steady state, the controlled gas pressure within the established limits is balanced by the adjusted spring and the valve is hermetically closed.
When the gas pressure in the network (also in the above-membrane cavity) exceeds the setting limit, membrane 6, overcoming the forces of spring 4, drops together with valve 3, opening the gas outlet to the atmosphere through the outlet pipe.
The gas will be released until the pressure in the network drops below the set value, after which, under the action of spring 4, valve 3 will close.
1 - body; 2 - cover; 3 - valve with guide; 4 - spring; 5 - adjusting screw; 6 - membrane; 7 - plate; 8 — spring plate
Equipment prices are available upon request.