Operation and performance inspection of pneumatic gate valve
1、 Operating mechanism
1) When the pneumatic valve is operated, the switch direction shall be closed clockwise.
2) As the pneumatic valves in the pipe network are usually opened and closed manually, the opening and closing turns should not be too much, that is, the large diameter valves should also be within 200-600 turns.
3) In order to facilitate the opening and closing operation of one person, the opening and closing torque shall be 240N-m under the working pressure of the pipe.
4) The opening and closing operating end of the pneumatic valve is a tenon, with standardized size and facing the ground, so that people can operate directly from the ground. Valves with discs are not suitable for underground pipe networks.
5) Display panel of opening and closing degree of pneumatic valve
① The scale line of the opening and closing degree of the pneumatic valve shall be cast on the gearbox cover or the display panel shell after the direction change, all of which shall face the ground, and the scale line shall be painted with fluorescent powder to show eye-catching;
② Stainless steel plate can be used as the material of indicator disk needle under good management, otherwise it is painted steel plate, and aluminum sheet is not used;
③ The indicator disc needle shall be eye-catching and firmly fixed. Once the opening and closing adjustment is accurate, it shall be locked with rivets.
6) If the pneumatic valve is buried deeply, the operating mechanism and display panel are far from the ground, and the extension bar facilities ≥ 1.5m shall be fixed firmly, so that people can observe and operate from the ground. In other words, the valve switch in the pipe network shall not be lowered into the well.
2、 Performance testing
1) When the valves are manufactured in batches, the following performance tests shall be carried out by the authority:
① Opening and closing torque of valve under working pressure;
② Under the working pressure condition, it can ensure the continuous opening and closing times of the valve;
③ Check the flow resistance coefficient of the valve under the condition of water delivery in the pipeline.
2) The following tests shall be carried out for valves before delivery:
① When opening the valve, the valve body shall withstand the internal pressure detection of twice the valve's working pressure value;
② When the valve is closed, both sides bear 1. The working pressure value of the valve is 1 time, without leakage; However, the leakage value of metal sealed butterfly valve shall not exceed relevant requirements.
