What is a Piston
Check Valve?
A piston check valve is self actuated ,one way valve,essentially a lift type check valve which
allows flow in one direction only.This valve is also Non-return Valve (NRV).
Construction and Operation of Piston Check
Valve
Construction of
the seat and disk of a piston check valve is the same as for lift check valves.
Main component of piston check valve is its dashpot. Dashpot of piston check
valve consists of a piston and cylinder that provides a cushioning effect
during operation. As the design of piston check valve is similar to lift check
valve, the flow characteristics through a piston check valve are also same as
through a lift check valve. Installation of this NRV(non-return valve) is the
same as for a lift check in that the flow must enter from under the valve seat.
Piston check
valve dimensions must be in accordance with the application or location of use
of valve.Piston check valve drawing must also be taken from supplier to have
complete understanding of valves parts .Piston check valve drawing also helps
HVAC engineers during the maintenance of valves.
Application/Use
of Piston Check Valve
Piston Check valves
are used in applications of water, steam, and air (compressible fluid). Piston
check valves are used basically in combination with globe valves and angle
valves in piping systems hence experiencing a number of changes in flow
direction of fluid.
