What are the conditions for repairing the pressure regulating valve?

Three points should be registered during the process of overhauling the pressure regulating and regulating valve: 1. The pressure regulating regulating valve is arranged in a combined manner, leaving one valve to be spared and several other valves are arranged in parallel. Determine the number and type of the shut-off valve in parallel, and the flow capacity reaches the Cv standard. In order to ensure that the operation of the pressure regulating and regulating valve does not overflow, the voltage stabilizer tower should be installed, so that the working pressure of the pipeline is as close as possible to the working pressure of the pipeline, so as to reduce the construction cost. If the voltage regulator tower is placed upstream of the pressure regulating regulating valve, it is bound to require the height of the voltage regulator tower to be higher than the water level of the engineering water inlet. Generally, the height of the voltage regulator tower will be high, the engineering investment will be increased, and the operation is inconvenient, so the pressure regulation is reduced. The pressure valve is placed downstream of the regulator. Second, the pressure regulating valve itself is very heavy, the outflow hole is small, and the structure is complicated. (For example, the pressure regulating valve of DN1800 weighs 28t, the debris in the pipeline water, such as branches, plastics, etc., once entering the valve body, it is easy to gate the valve cavity and the outflow hole, need to be set into the manhole to adjust the pressure regulating valve Carry out general maintenance, remove debris, and solve the problem of repairing after removing the pressure regulating and regulating valve. In order to be inspected, it is necessary to set one butterfly valve in front of the valve and behind the valve (the inlet hole is set in the butterfly valve and pressure regulating) In between the regulating valve, to cut off the water in the upstream and downstream pipelines. In order to ensure a stable flow of water and to avoid cavitation butterfly valves, the distance between the regulating pressure regulating valve and the valve butterfly valve must meet the length requirements of the straight pipe before and after the valve. Third, the opening of the pressure regulating butterfly valve needs to rely on (pre-valve, post-valve, flow) sensors to transmit the flow signal or pressure to the control room, and the control room controls according to the need. To obtain a stable signal, it is required before and after the valve. The flow of water should be stable. Generally, the length of the pipe in front of the valve is 35 times the length of the pipe. After the valve is operated by the pressure regulating valve to cause the swirling flow to dissipate, a lot of bubbles to be exploded will be formed in the pipe. Rear straight pipe length Not less than 5 times the length of the pipe diameter.