H42 vertical check valve is designed and manufactured in strict accordance with API6D, GB/T12235 standard, this series of valves are normally in the closed state, due to the pressure of the inlet medium in the pipeline, and overcome the spring resistance to open the valve. When the pressure of the medium at the inlet end is lower than the outlet end, the spring pushes the spool to the valve seat to close the valve and prevent the medium from flowing back, so it plays a check role. H42N vertical check valve can be installed vertically or horizontally because of the spring-supported spool. Vertical check valves are widely used in pipelines under various working conditions such as petroleum, chemical, pharmaceutical, and power industries.