What is a swing check valve?
What is a swing check valve?
In swing check valves, a flapper will swing away to allow forward flow of a fluid or gas. When it is time to stop the flow, the flapper will swing back onto the seat, closing the valve automatically as the system pressure decreases. Swing check valves are notable due to their large flow capacity.
Do swing check valves leak?
Swing check valves use a hinged swinging disc to block and control the movement of fluid in a system. As they are used to prevent the reverse flow of fluids or gases, any failure can lead to leakage, loss of pressure, contamination, overflow, and, in the most severe cases, complete system failure.
How do you test a swing check valve?
Slowly open the small test port cap on the top of the check valve until water starts to slowly bleed out. 4. Turn off the supply valve (inlet valve on a meter setter, or other valve upstream of the check valve). The flow should stop coming out of the test port within 2-5 seconds, relieving the pressure in the meter.
Do check valves fail open or closed?
One, check valves are prone to jamming in the open position, thereby becoming an uncheck valve of sorts. Two, they are prone to jamming in the closed position, preventing water flow in any direction. If the check valve is stuck open, the pump runs and pumps just fine; however, it won’t prevent backflow or flooding.
Can a check valve be installed upside down?
Check valves MUST be installed with the valve’s FLOW arrow pointing in the direction of the flow. In horizontal installations, the designated side must be positioned “up”. Do Not install Check Valve upside down.
What can a prince wafer check valve be used for?
Maintenance is minimal with the field replaceable O-ring seat available in all styles and sizes. The Prince Wafer Check Valve is used to stop flow reversal in chemical refineries, ammonia compressors, waste water treatment plants, HVAC systems and most other industrial applications
How big is the Keystone Prince swing valve?
KEYSTONEPRINCE WAFER SWING CHECK VALVES FIGURES 809 TO 815 TECHNICAL DATA Size range: NPS 2 to 36 Pressure rating: 150 – 740 psi ASME flange rating: 125 – 300 GENERAL APPLICATION
How does the external spring work in Prince check valves?
For media containing fibrous matter or caustics, Prince offers an external spring (Figure 813 and Figure 815) which eliminates the spring from the flow path. This will prohibit the possibility of fiber wrapping around the spring or chemical attack of the spring.
What do you need to know about swing check valves?
The check valve shall be a wafer style (flangeless) swing check design utilizing an external torsional spring to assist in faster closure. The valve must be capable of gravity closure should the loss of spring tension occur when system back pressure is present. The valve shall have capability to add lever and/or weight for back-flush capabilities.
