Two, the regulating valve is very heavy, the outlet hole is small and the structure is complex. (for example, the pressure regulating and regulating valve of DN1800 is up to 28T, such as branches and plastics, such as branches and plastics in the pipe water, is easy to enter the valve cavity and outlet. It needs to be set into the manhole to carry out general maintenance, remove the sundries, and solve the problem of overhaul after dismantling the pressure regulating and regulating valve. In order to be able to be checked and overhauled, 1 butterfly valves should be set in front of the valve and after the valve (the manhole is set between the butterfly valve and the pressure regulating valve) to cut off the water in the upstream and downstream pipelines. In order to ensure stable water flow and avoid cavitation butterfly valve, the distance between pressure regulating and regulating valve and butterfly valve must meet the requirement of straight pipe length before and after valve.
Three, the opening degree of the pressure regulating butterfly valve needs to be transferred to the control room by the sensor (front of the valve, after the valve and flow), and the control room is controlled by the control room. To obtain a stable signal, the flow of the front and rear valves of the valve is required to be stable. Generally, the length of the pipe is 35 times the length of the straight pipe, and after the valve causes the flow to generate swirling energy, many bubbles to be exploded are formed in the pipe, and the length of the straight pipe length is not less than 5 times the length of the pipe. Degree.