A check valve has been designed to let liquids and gases pass through it in a unidirectional flow. This apparatus is applied across residential and commercial plumbing, industrial piping, and watering systems.
Different types of check valves exist, such as ball check valves, disk check valves, and diaphragm check valves; each offering unique benefits and drawbacks. Thus, it is critical to pick the appropriate type of valve for the job at hand.
The popular ball check valve is a simplistic device that functions straightforwardly. It is composed of a ball and a spring encased within the valve’s body. Once fluid passes through in the acceptable direction, the pressure from the incoming liquid pushes the ball open. When reverse flow occurs, the spring encased inside forces the ball shut thus barring any reverse motion.
A disk check valve differs from a ball check valve in that, instead of incorporating a ball, it employs a disk to hold down a spring. Due to its construction, a disk check valve is capable of providing improved leak-resistance as compared to its ball-bearing counterpart; however, it is also more likely to end up fixed in either the open or closed position.
Using a flexible diaphragm held in place by a spring, diaphragm check valves open when fluid forces them in the correct direction. In contrast, when force is applied in an opposite direction, the spring holds the diaphragm closed, barring the flow of fluid. Though less prone to getting stuck than ball or disk check valves, they are more apt to leak.
Enhanced strength and longevity make brass an optimal material for check valves. These valves come in different sizes and connector styles, such as the male threaded – featuring external threads that attach to female threads on pipes and attachments – and the female threaded – which have inner threads that line up with male threads on pipes and fittings.
By utilizing compressed air, check valves can be conveniently operated. As such, these valves are labelled as “pneumatically operated” when compressed air is employed. Notably, various sizes and connection types of pneumatic check valves exist on the market.
When searching for the perfect check valve, a few essential aspects must be taken into account. This includes which kind of liquid will be moving through, the pressure at its highest peak, the maximum temperature of operation, and of course, the necessary flow rate.