
Check it out - a 2-1/2" clear PVC true union swing check valve. This valve is made of clear PVC with socket style ends. See what is happening inside the valve and make sure your backflow is being stopped by the valve and that flow is allowed in the other direction.
Size: 2-1/2"
End Type: Socket
Schedule: 140 PSI Full Flow, 75 PSI Back Pressure
Flow Velocity: Should not exceed 5ft/sec
Minimum Opening Pressure: Less than .5 PSI