Safety Pressure Reducing Valve

Safety Pressure Reducing Valve ART.N10151004, is one of types of safety valves for drinking water system, uses the opening degree of the opening and closing parts in the valve body to adjust the flow of the medium, reducing the pressure of the medium, and at the same time adjusting the opening degree of the opening and closing parts by the pressure after the valve, so that the pressure after the valve is maintained at Within a certain range, when the inlet pressure is constantly changing, keep the outlet pressure within the set range to protect the subsequent living and production appliances.

Safety pressure reducing valve is to keep the outlet pressure and temperature within a certain range when the inlet pressure is constantly changing, is an essential accessory of the pneumatic regulating valve. Its main function is to reduce the pressure of the air source and stabilize it to a fixed value, so that the regulating valve can obtain a stable air source power for regulating control. Select the type and pressure regulation accuracy of the pressure reducing valve according to the requirements of use, and then select its diameter according to the required maximum output flow. When determining the air source pressure of the valve, it should be greater than the maximum output pressure of 0.55 MPa. The safety pressure reducing valve is generally installed after the water separator and before the lubricator or the setting device, and be careful not to connect its inlet and outlet reversely; when the valve is not in use, the knob should be loosened to prevent the diaphragm from being constantly compressed and deformed. Its performance. This type of valve should generally be installed horizontally in the pipeline.

The compressed air with pressure P1 is input from the left end and throttled by valve port 10, and the pressure drops to P2 output. The size of P2 can be adjusted by adjusting springs 2 and 3. Rotate the knob 1 clockwise, compress the springs 2, 3 and the diaphragm 5 to move the valve core 8 down, and increase the opening of the valve port 10 to increase P2. If the knob 1 is turned counterclockwise, the opening of the valve port 10 decreases, and P2 decreases accordingly.

If P1 rises instantaneously, P2 will rise accordingly, causing the pressure in the diaphragm chamber 6 to increase, and the thrust generated on the diaphragm 5 will increase accordingly. This thrust destroys the balance of the original force and causes the diaphragm 5 to move upward. Moving, a small part of the air flow is discharged through the overflow hole 12 and the exhaust hole 11. As the diaphragm moves up, due to the action of the return spring 9, the spool 8 also moves upward, closing the intake valve port 10, and increasing the throttling effect, causing the output pressure to drop until a new balance is reached. The output pressure is basically Back to the original value. If the input pressure drops instantaneously, the output pressure also drops, the diaphragm 5 moves down, the spool 8 moves down accordingly, the intake valve port 10 opens, the throttling effect is reduced, and the output pressure basically returns to its original value. Turn knob 1 counterclockwise. The adjusting springs 2 and 3 are relaxed, the thrust of the gas acting on the diaphragm 5 is greater than the force of the pressure adjusting spring, the diaphragm is bent upward, and the inlet valve port 10 is closed by the action of the return spring. Turn the knob 1 again, the top of the intake valve core 8 and the overflow valve seat 4 will disengage, and the compressed air in the diaphragm chamber 6 will be discharged through the overflow hole 12 and the exhaust hole 11, leaving the valve in a non-output state .

In short, the overflow pressure reducing valve relies on the throttling effect of the air inlet to reduce pressure, and relies on the balance of the force on the diaphragm and the overflow effect of the overflow hole to stabilize the pressure; the output pressure can be changed within a certain range by adjusting the spring. . In order to prevent the pollution of the surrounding environment caused by a small amount of gas from the above overflow type pressure reducing valve, a pressure reducing valve without an overflow valve (that is, an ordinary pressure reducing valve) can be used.

When the output pressure of the pressure reducing valve is high or the diameter is large, if the pressure is directly adjusted by the pressure adjusting spring, the spring stiffness must be too large. When the flow changes, the output pressure fluctuates greatly, and the structural size of the valve will also increase. In order to overcome these shortcomings, a pilot-operated pressure reducing valve can be used. The working principle of the pilot-operated pressure reducing valve is basically the same as that of the direct-acting type. The pressure regulating gas used in the pilot pressure reducing valve is supplied by a small direct-acting pressure reducing valve. If a small direct-acting pressure reducing valve is installed inside the valve body, it is called an internal pilot pressure reducing valve; if a small direct-acting pressure reducing valve is installed outside the main valve body, it is called an external pilot pressure reducing valve . Compared with the direct-acting pressure reducing valve, the structure of the internal pilot-operated pressure reducing valve adds a nozzle baffle amplification link composed of nozzles, baffles, fixed orifices and air chambers. When the distance between the nozzle and the baffle changes slightly, the pressure in the B chamber will change significantly, which will cause the diaphragm 10 to have a larger displacement to control the up and down movement of the valve core 6 to make the inlet The air valve port 8 is opened or closed, which improves the sensitivity of the valve core control, that is, the accuracy of voltage stabilization is improved.

The main valve of the external pilot-operated pressure reducing valve has the same working principle as the direct-acting type. There is also a small direct-acting pressure reducing valve outside the main valve body, which controls the main valve. This type of valve is suitable for occasions with a diameter above 20mm, long distances (within 30m), high places, dangerous places, and pressure regulation difficulties. Steam pressure reducing valve

The setting device is a high-precision pressure reducing valve, mainly used for pressure setting. There are currently two types of pressure regulators: the gas source pressure is 0.14MPa and 0.35MPa, and the output pressure ranges are 0-0.1MPa and 0-0.25MPa. Its output pressure fluctuation is not more than 1% of the maximum output pressure. It is often used in occasions that require accurate air source pressure and signal pressure, such as pneumatic experimental equipment, pneumatic automatic devices, etc.

1. For the convenience of operation and maintenance, the safety pressure reducing valve is generally installed upright on a horizontal pipeline.

2. The installation of the safety pressure reducing valve must be strictly in accordance with the direction of the arrow on the valve body to maintain the same direction as the fluid flow. If the water is not clean and contains some impurities, a filter must be installed at the upstream water inlet of the brass pressure reducing valve (we recommend that the filtration accuracy is not less than 0.5mm).

3. In order to prevent overpressure behind the valve, a brass pressure reducing valve should be installed no less than 4M away from the valve outlet.

4. The safety pressure reducing valve plays a certain role in the pipeline. In order to prevent the harm of water hammer, a small expansion tank can also be installed to prevent damage to the pipeline and valve. The filter must be installed in the brass pressure reducing valve. Before the inlet pipe, and the expansion tank must be installed behind the outlet pipe of the brass pressure reducing valve!

5. If you need to install the safety pressure reducing valve in the hot water system, you must install an inlet check valve between the brass pressure reducing valve and the expansion tank. In this way, the expansion tank can not only absorb the volume of water increased due to thermal expansion, but also prevent the influence of hot water backflow or pressure fluctuation on the brass pressure reducing valve, and ensure the long-term normal operation of the brass pressure reducing valve.

1. The basic performance of the safety pressure reducing valve is as follows: the pressure regulating range is mainly related to the stiffness of the pressure regulating spring, and the pressure regulating range is within the specified range of the output pressure P2 of the water pipe pressure reducing valve, and it must be ensured to achieve the specified accuracy. When the flow rate g is a constant value, fluctuations in the input pressure will cause fluctuations in the output pressure. When the output pressure fluctuates less, the characteristics of the pressure reducing valve are better, so the output pressure must be lower than the input pressure-a fixed value so that the pressure range does not change with the input pressure. At the input pressure-timing, the output pressure will change with the change of the output flow g.

2, close the on-off valve in front of the safety pressure reducing valve, and open the on-off valve after the pressure reducing valve to create a downstream low-pressure environment; turn the adjusting screw counterclockwise to the upper position (relatively low outlet pressure), and then close the on-off valve after the pressure reducing valve;

3. Slowly open the on-off valve in front of the safety pressure reducing valve to fully open; slowly turn the adjusting screw clockwise to adjust the outlet pressure to the required pressure (subject to the gauge pressure after the valve); after adjustment, lock it , Lock the nut, open the pressure reducing valve and then the gate valve; Note: Only adjust from low pressure to high pressure