PVC spring check valves. 

A spring check valve is a one-way valve that uses a metal spring to push a door closed. In a pond, it stops water from flowing backward through your plumbing when the pump shuts off. This prevents your pond filters from emptying and your external water pumps from losing their prime.

Why Choose a Spring Check Valve?
Stops Reverse Flow: It instantly stops water from flowing backward into your skimmer when the pump is off.
Prevents Overflows: It stops tall waterfalls or elevated filters from emptying and overflowing your pond basin.
Positive Seal: The spring ensures the valve closes completely, even without water pressure helping it shut

Available in Slip to Slip style. Slip to Slip (S x S) is a smooth walled check valve which your PVC pipe can slide into and be cemented in place. 

•   Ideal for use in fresh or salt water, are rated to 100 PSI, mounted vertical or horizontal, and can be used with schedule 40 or 80 PVC pipe

S x S Spring Check Valves

Swing, S x S, PVC SCH 40


Swing vs Spring:
Swing check valves utilize a disc attached to a hinge which allows it to swing freely. When there is downstream pressure, the disc swings away from the valve seat to allow the liquid to flow through. Reverse flow is stopped by the disc swinging back into place due to gravity or back pressure. Generally, swing check valves allow for higher flow capacity compared to spring check valves but are often noisier and are limited by their orientation.

Spring check valves are suitable for use in both vertical and horizontal orientations and are ideal for applications that require quick responses to flow changes. They use a closing mechanism, such as a disc or poppet, combined with a spring that allows for downstream flow but stops reverse flow altogether. When compared to swing check valves, spring check valves tend to be more compact in design, making them suitable for installation in tight spaces. They also tend to be quieter, while the spring mechanism ensures a faster response to backflow.