Structural features:

① Lift through check valve
The main model number is H41S, which is generally similar in structure to a globe valve. Its valve disc moves up and down along the center of the channel with reliable action, and can only be installed on horizontal pipelines.
② Shenglong vertical check valve
The main models are H42S and H40S, among which H40S is a new type of structure with a spherical valve disc. The common feature is that the valve disc moves up and down along the uranium line of the valve body passage, and should generally be installed in a vertical pipeline.
③ Swing check valve
The main models include H44S, H74S plastic single disc swing type, and H76S double disc swing type. The valve disc rotates around the axis, and its fluid resistance is generally lower than that of the lift check valve. It is suitable for larger diameter applications, and the installation position is not limited. It is usually installed in horizontal pipelines.
④ Butterfly check valve
The main model is H47P0, with a soft sealed double eccentric flange connection structure. The micro resistance slow closing butterfly check valve is designed with a slow closing device outside the valve, which is beneficial for reducing flow resistance and vibration, and minimizing the impact of water hammer.
　
Execution standards:

① Design and Manufacturing: Q/ZXD01-1999 GB/T13932-92 GB/T12235-89 GB/T12236-89 JIS standard.
② Flange size:
PN=1.0MPa according to JB/T82.1-94 (original standard JB82-59) "Convex Welding Steel Pipe Flanges".
PN=1.6MPa according to GB9113.3-88 "Convex Integral Steel Pipe Flanges".
PN=2.5MPa according to GB9113.4-88 "Convex Integral Steel Pipe Flanges".
③ The structural length shall be in accordance with GB12221-89 "Structural Length of Flanged Metal Valves".
④ Inspection and testing shall be conducted in accordance with GB/T13927-92 "General Valve Pressure Test".

Technical parameters:

Flange connected plastic lined check valve (swing type, straight through lifting type):