Many valves have directional, such as globe valve, throttle valve, reducing valve, check valve, etc., if installed inverted reverse, it will affect the effect and life (such as throttle valve), or not at all (such as reducing valve), or even cause danger (such as check valve). General valve, on the valve body has the direction mark; In case of failure, the valve should be identified according to its working principle.
Gate should not be inverted, otherwise the medium will be retained in the cover space for a long time, it is easy to corrode the stem, and some process requirements taboo. It is extremely inconvenient to change the packing at the same time.Rising stem gate valves, do not install underground or corrode exposed stem due to moisture. Lift check valve, installed to ensure that its disc vertical, in order to lift flexible. Swing check valves should be installed with the pin level in order to be flexible. Pressure relief valve to be installed in the vertical horizontal pipeline, all directions do not tilt.
