Pressure Regulator Valve is also named the pressure reducing valve. Pressure reducing valve is widely used in fire water supply and automatic sprinkler systems. Today, we will learn the working principle of pressure reducing valve and its setting requirements.
1. HOW IT WORKS
1) Pilot Operated Pressure Regulating Valve
After changing the throttling area, the velocity and the kinetic energy of the fluid in the pipeline system are changed, and the pressure loss of different degree is produced, the pilot type pressure reducing valve can achieve the goal of reducing the pressure in the pipeline Let the valve internal pressure fluctuations and spring force to achieve a balance, so that the final pressure in the pipeline after the valve to maintain a certain error within a constant range.
The pilot type pressure reducing valve uses the hydraulic pressure principle to realize the control. The pilot type pressure reducing valve, as a component of local pressure change adjustment and throttling, reduces the inlet pressure to a certain range of outlet pressure by adjusting the inlet pressure, and then relies on the energy of the medium itself A valve that automatically keeps the outlet pressure stable.
2) Proportional Pressure Regulating Valve
Proportional pressure relief valve is a valve in accordance with the numerical proportion to control the pressure after the valve, the pressure before the valve and after the valve pressure ratio of 2:1,3:1, etc. . The pressure after the valve changes with the change of the pressure before the valve, the pressure after the valve is not kept constant, but with the pressure before the valve to maintain a certain ratio. When the pressure in front of the valve increases, the pressure in front of the valve increases proportionately. When the pressure in front of the valve decreases, the pressure in front of the valve decreases proportionately.
2. SETTING REQUIREMENTS
1. The pressure reducing valve should be set before the inlet of the alarm valve group. When connecting two or more alarm valve groups, the spare pressure reducing valve should be set.
2. The inlet of the pressure-reducing Valve shall be provided with a filter whose mesh diameter shall not be less than 4 MESH / C ~ 5 Mesh / C and the flow area shall not be less than 4 times of the cross-sectional area of the pipeline.
3. Pressure Gauges shall be installed before and after the filter and the pressure reducing valve. The dial diameter of the gauge shall not be less than 100mm. The maximum measuring range shall be 2 times of the design pressure.
4. Control Valves shall be provided in front of the strainer and after the pressure reducing valve.
5. A pressure test drain valve shall be installed after the pressure reducing valve.
6. Pressure Relief Valve shall be provided with flow test interface or flow meter.
7. Vertical installation of pressure relief valve, the flow direction should be down.
8. Proportional pressure reducing valve should be installed vertically, adjustable pressure reducing valve should be installed horizontally.
9. Pressure Relief Valve should be protected or locked regulating accessories device.
10. Connect the pressure-reducing valve pipe should not have air block, air resistance.
Note:
1) The performance of the pressure relief valve requires that the direction of the water flow should not be changed. Proportional pressure relief valve, if the direction of the water flow changed, the pressure reduction into a boost; adjustable pressure relief valve, if the water flow in the opposite direction, can not work, pressure relief valve into a check valve. Therefore, installation should be strictly in accordance with the direction indicated by the pressure relief valve installation.
2) It is required to install the filter on the inlet side of the pressure reducing valve, which is mainly to prevent the sundries from flowing into the pressure reducing valve, blocking the path of the pilot valve of the pressure reducing valve, or depositing on the movable parts in the pressure reducing valve, thus affecting its action and causing the failure of the pressure reducing valve. Pressure relief valve before and after installation of Control Valve, mainly to facilitate maintenance and replacement of pressure relief valve, in maintenance, replacement of pressure relief valve, reduce the system drainage time and the impact of water suspension.
3) The valve core of the proportional pressure reducing valve is a cylinder piston structure, and the positioning seal depends on the rubber sealing ring of the valve core coat and the valve body. Vertical installation, the valve core and the valve body sealing contact surface and force more uniform, to ensure the reliability of its performance and extend the service life. Such as horizontal installation, its SPOOL and valve body due to gravity, easy to cause lower contact tight, increase friction resistance, affect its decompression effect and service life. When installed horizontally, the single-hole aspiration is downward and the double-hole aspiration is horizontal, mainly preventing the external sundries from clogging the aspiration hole and affecting its performance.
4) Installation pressure gauge, mainly for debugging can check the pressure relief effect of pressure relief valve, in use can always check the water supply pressure, pressure relief valve pressure after the design requirements, that is, whether the pressure relief valve working condition is normal.
3. COMMISSIONING OF PRESSURE REDUCING VALVE
1) The static and dynamic pressure of the Front Valve and the back valve of the pressure reducing valve should meet the design requirements.
2) The outlet flow rate of the pressure reducing valve shall meet the design requirements. When the outlet flow rate is 150% of the design flow rate, the dynamic pressure behind the valve shall not be less than 65% of the rated design pressure.
3) No significant increase in noise shall occur at low flow, design flow, and 150% of design flow for pressure relief valves.
4) The static and dynamic pressure difference after testing the pressure reducing valve should meet the design requirements.
4. MAINTENANCE OF PRESSURE REDUCING VALVE
1) The pressure relief valve group shall be drained once a month and the pressure before and after the relief valve shall be tested and recorded, and when the design value is not met, such measures as commissioning and maintenance shall be taken to meet the requirements of the system.
2) The flow and pressure of the relief valve shall be tested annually.
Post time: Jul-28-2021