Cast Steel Swing Check Valve Class150-1500 Non-return Valve WCB
Flanged
Swing check valves are the most common and best check valve for
general-purpose use. Of all check valve designs, these valves
produce the lowest pressure drop, when compared with other check
valves of the same size. They feature a simple design that is easy
to maintain.
The swing check valve functions by allowing flow forces to move the
disc from the closed position to the fully open position in a
sweeping arc motion against the hinge-stop inside of the valve
body. Due to the weight and center-of-gravity location of the disc
and swing-arm assembly, the valve will return to the closed
position should flow become interrupted or reversed. External
counterweights mounted on the hinge pin are sometimes used to
increase or decrease the reaction time and speed of the disc
returning to the closed position. Seating surfaces are typically
flat, which means the radial disc positioning onto the seat is not
critical, except that it must be flat onto the seat.
Swing check valve discs are not stable unless they are in systems
with a steady flow and are in the fully open position. As the
disc/hinge assembly center of rotation is a fair distance from its
pivot point, it will take a relatively long period of time for
swing check valves to close upon flow stoppage or reversal. During
this time, reverse-flow forces may experience a large increase in
energy from flow and pressure buildup. This situation can cause
high-energy water hammer when the disc slams onto the seat.
The Swing Check Valve can be enhanced with many options such as a
lever and weight, which is designed to make the valve close faster
and prevent slamming.
Features of Swing Check Valves:
Swing Disc Design
Bolted Cover
Internal Hinge Pin Design Standard
Through-body Hinge Pin Design Available
Renewable Seat
Flanged or Butt-welding Ends
Extra Lever, Counter Weight, and Damper Available
Applicable Standards of Swing Check Valves:
a) Design&Manufacture:API 6D, BS 1868, ASME B16.34
b) Face to Face: API 6D, ASME B16.10, EN 558
c) Connection End: ASME B16.5, ASME B16.25, EN 1092, JIS B2220
d) Test and Inspection: API 6D, EN 12266, API 598, BS 6755
