Exhaust valve type selection in the engineering design, various types of exhaust valves shall be selected according to the specific site conditions, and composite exhaust valves shall be installed at the local highest points; For long-distance horizontal pipe section and long-distance descending pipe section without break point, composite exhaust valve or micro exhaust valve should be installed; For the points where the descending slope becomes larger and the ascending slope becomes smaller, the micro exhaust valve should be selected; When vacuum protection is required, composite exhaust valve shall be selected; Composite exhaust valve can be selected for long-distance riser without break point.

 

The diameter of exhaust valve is micro exhaust valve, which can be directly selected due to its small application range. Generally, the pipe diameter is DN20 and DN25; Since the composite exhaust valve is a combination of micro exhaust valve and high-speed exhaust / suction valve, the diameter selection criteria of composite exhaust valve and high-speed exhaust / suction valve are the same.

 

According to the performance curve, since the high-speed exhaust / suction valve is used to remove air during water filling and suction during venting, the amount of air excluded during pipeline water filling (exhaust) and the amount of air inhaled during pipeline drainage venting or pipe burst protection (suction) shall be comprehensively considered, both the diameter of exhaust port during water filling and the diameter of suction port during emptying shall be calculated, Select the larger diameter as the diameter of exhaust / suction valve.