VALVE

  Check valves   may be the most easily misunderstood valve in history. If you mention check valves to most factory personnel, the typical reaction is "they don't work.". In fact, these personnel are likely to have removed internal components or refurbished the system to avoid using check valves. In other words, these valves may be the least popular valves currently in use. This article will explore the basic knowledge of check valves, how they work, what types they are, how to select and install them, how to solve their problems, and why they are not always problems. Simply put, check valves allow one-way flow and automatically prevent backflow (backflow) when the fluid in the pipeline is reversed. They are one of the few automatic valves that do not require auxiliary opening and closing. Although some valves can be equipped with external counterweights and damping devices in special circumstances, most valves do not have open/close control or external assistance from ot...