How To Choose a Pool Check Valve - Overview

There are several types of pool Check Valves. This guide provides an overview of the function, description, and repair or replacement of these Check Valves.

1. CHECK VALVE PURPOSE - In general a pool check valve in installed in your circulation system to keep water from flowing backwards in the system when the pump is turned off. 

2. CHECK VALVE TYPES - There are two common types of Check valves on the market today: the Spring Check Valve and the Spring Flapper Check Valve. The Spring Check Valve has an internal panel that moves against a light spring to open and shut the valve. The Spring Flapper Check Valve has a flap on one end of the valve that pivots up against a light spring when water is flowing from the pump, then releases down to shut off any opposite flow when the pump is off.

3. SPRING FLAPPER CHECK VALVE - This picture shows the two popular styles of Spring Flapper Check Valve. Both provide access to the flapper mechanism from the top of the valve. One is screwed down with 8 screws. The other is secured with a more convenient twist on Cover Nut.

4. SPRING FLAPPER MECHANISM - This picture shows the flapper mechanism that operates inside a typical Spring Flapper Valve. The Flapper is accessed by removing the top of the valve.

5. SPRING CHECK VALVES - This picture shows the center panel inside a typical Spring Check Valve. I have used a stick to push the center of the panel to allow flow through the valve. This Check Valve does not open as much as the Flapper valve so would appear to impede flow more than the Flapper Valve.

6. CHECK VALVE SIZES - These Check Valve come in different port sizes to fit the common system piping including 1 1/2, 2" and 2 1/2". Some of the valve are designed to fit two sizes. For example, a 1 1/2 pipe would fit inside the port, and a 2" pipe would fit outside the port. Also these valve come with different spring strengths. Most have a 1/2 # spring for light resistance. Some have 2# resistance for situations with greater head or backflow pressure like solar panels mounted on an 8' high roof.

7. CLEAR VS OPAQUE - You can purchase opaque or clear Check Valves. With a clear valve you can see the spring mechanism to determine if it is clogged with debris or if the spring is weak and won't completely close the valve.

8. UNION VS NON-UNION - Valve come with and without unions. Unions allow you to remove the valve for cleaning without having to cut the valve out of the plumbing. Some valves can be accessed and repaired through the top of the valve. For these types, the valve body does not need to be removed and is typically installed into the plumbing without unions - commonly referred to as a "slip" connection - pipe "slips" into the valve and is permanently glued.

9. CLEARING DEBRIS - Debris will occasionally get caught in the valve keeping it from closing completely.

10. REPAIRING A CHECK VALVE - If the spring mechanism in a Check Valve is weak or broken, you will have to replace it. Unfortunately, not all Check Valve can be repaired. The Spring Check Valves discussed above cannot be opened for they must be replaced. On a Spring Flapper style Check Valve, the Flapper mechanism can be accessed and replaced through the top of the valve. 

11. REPLACING A CHECK VALVE - To replace a Spring Check Valve see "How to Change a Pool Spring Check Valve". To replace a Spring Flapper Check Valve see "How To Change a Pool Spring Flapper Check Valve".

If you have any other questions about pool and spa products please do let us know - we are here to help! 

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