Vertical & Horizontal Check Valves Resistoflex Horizontal and Vertical Poppet-Type Check Valves are plastic-lined for handling corrosives and high-purity fluids. They are extremely effective in preventing back-pressure or backflow, feature a low 0.5 psi (0.03 bar) cracking pressure differential, and are capable of handling pressures to 275 psi (19 bar). Liner materials of polypropylene resin, PVDF resin, or PFA resin are available, depending on the valve size and type. Full size ports for maximum capacity Resistoflex Check Valves, available in 1” through 8” sizes, have full pipe diameter ports and provide minimal obstruction in the flow path. The poppet-type design of the vertical check valves eliminates problems that occur in some check valves with pockets that can trap fluid. Practically maintenance-free Since Resistoflex Check Valves have only one moving part, they are less likely to need maintenance. Because every surface in contact with the fluid is made of or covered with a thick layer of plastic, corrosion and contamination are vitually eliminated. Available models and sizes Size, inches 1 1 1/2 2 3 4 6 8 Body Material DI CS DI CS DI CS DI CS DI CS DI CS DI CS PP X X X X X X X X X X X X X X PVDF   X   X   X   X   X   X   X PFA   X   X   X   X   X         DI = Ductile Iron       CS = Cast Steel
Pressure/temperature ratings for Resistoflex check valves		1. Class 150 Cast Steel 1" - 4" valves 2. Class 150 Cast Steel 6" - 8" valves 3. Class 150 Ductile Iron †Maximum liner/diaphragm capabilities may be lower depending on the agressiveness of the fluid being handled. Refer to the Chemical Resistance Guide.
Calculating pressure drop The Cv values given in the table below can be used to approximate pressure drop (ΔP), in psig, across the valve when the required flow (Q) in gallons per minute is know by using the following formula: G = specific gravity ΔP = G(Q/Cv)2 Positioning hint for check valves To prevent excessive poppet wear, it is recommended that the piping from the pump discharge to the valve be at least 10 feet in length and include a change in direction. Valve Cross Reference Horizontal Check Valve Dimensions Vertical Check Valve Dimensions Valve Specifications Storage, Installation, Testing, Operation and Maintenance Guidelines for Vertical Check Valves