Check Non-Return Valves
JV Check / Non-Return Valves are designed and manufactured according to BS1868. Check valves in piping systems in all fields are considered very critical in their application. The function of check valves is to prevent the reverse flow of fluids e.g. in case of failure or sudden shutdown of the piping system. The Sealing efficiency, therefore, is a very critical aspect of check valves.
JV Check Valves
JV Check Valves are available in wide variety of materials such as Cast Iron, Cast Carbon Steel, Cast Stainless Steel of all Grades, High Alloy Steels like Alloy-20, CD4MCu and Hastelloy. Manufacturing ranges 50NB to 600NB and Pressure Rating from ANSI 125# to 1500#.
Dual Flap Check Valves
These check valves are of wafer design and fit between flanges.
The valve discs are in two halves and held in the closed position by a stainless steel spring.
The reaction of the stainless steel spring quickly and quietly shuts the valve off before the flow in the line can reverse. Water hammer is virtually eliminated.
These valves can be installed in any position.
Lift or Piston Check Valves
This type of check valve uses a piston rather than a hinge mounted disc to prevent the reversal of flow. This provides a cushioning effect during operation. These valves can only be used in a horizontal position.
Lift check valves and globe valves are flow restricting and therefore often used in conjunction.
Air Check Valves
These check valves are specifically designed for compressed air services.
The disc is manufactured from flat stainless steel and held against the seat by a spring whilst the compressor is idling or in-operative. It is recommended that the valve be located at least 3 metres from the compressor.