Valve size has the following steps:

1: Close the gate valve in front of the pressure reducing valve, open the gate valve after the pressure reducing valve, and create a downstream low-pressure environment;

2: Turn the adjusting screw counterclockwise to the uppermost position (relative to the lowest outlet pressure), and then close the gate valve after the pressure reducing valve;

3: slowly open the valve before the gate valve to fully open;

4: Slowly turn the adjusting screw clockwise to adjust the outlet pressure to the required pressure (the gauge pressure behind the valve shall prevail);

5: After adjustment, lock the nut and open the gate valve after the pressure reducing valve

9.3.5 The setting of the pressure reducing valve shall meet the following requirements:

1. It shall be set in front of the entrance of alarm valve group;

2. A filter should be set before the entrance, and it is convenient for sewage discharge;

3. When connecting two or more alarm valve groups, a standby pressure reducing valve should be set;

4. For the pressure reducing valve set vertically, the water flow direction should be downward;

5, proportional pressure reducing valve should be set vertically, adjustable pressure reducing valve should be set horizontally;

6, the pressure reducing valve should be set before and after the control valve and pressure gauge, when the main valve body of the pressure reducing valve itself with a pressure gauge, can not set the pressure gauge;

7, pressure reducing valve and before and after the valve should have protection or locking adjustment fittings device.