Check valves

[Anthony5]

I have the Astral check valves, spring type, and those who use them will know that they are a pain in the arse as they frequently stay open because some dirt get inside.

Today was the 3rd time that me Hayward pump ran completely dry for over an hour. Lucky it's a Hayward, since all other pumps would have been ready for the scrapyard, but my pump is still functioning.

Reason is my waterfall is connected to the main drain, and if I run the waterfall while the check valves aren't closed. it will suck the pool pump dry.

Has someone a solution for it?

Are ball valves more secure or are there spring type valves that don't have this problem?

[SwimmingPoolsThailand]

Spring/cone type check valves by Peraqua, Austria, Europe are excellent quality and have no known issues.

There are some cheaper, near identical ones, on the market here in Thailand but the spring rusts away after about one year and the cone has no support left and sticks in either a closed, fully open, or half-open position.

There are also others on the market with a near identical casing that have a ball inside that has no spring. They close well when under pressure, but may leak when only closed under gravity of the water on top, hence they should be installed in a vertical position only.

Emaux manufacture a flap type check valve with a clear-view lid. very efficient but should always be installed horizontally, or vertically with the flap by default in the closed position.

Spring type check valves have very strong springs and can significantly reduce the water flow - especially when used with smaller pumps (e.g. under 1HP), while with flap types the resistance to the water flow is negligible.

The term 'ball-valve' is usually used for a tap because inside they have a ball with a hole for the water to pass through.

It would be inaccurate to assume that all other quality brands of pumps other than Hayward are not equipped with 'no flow' protection. That said, we have known plenty of Hayward pumps to run dry and seize.

[Anthony5]

Spring/cone type check valves by Peraqua, Austria, Europe are excellent quality and have no known issues.

There are some cheaper, near identical ones, on the market here in Thailand but the spring rusts away after about one year and the cone has no support left and sticks in either a closed, fully open, or half-open position.

There are also others on the market with a near identical casing that have a ball inside that has no spring. They close well when under pressure, but may leak when only closed under gravity of the water on top, hence they should be installed in a vertical position only.

Emaux manufacture a flap type check valve with a clear-view lid. very efficient but should always be installed horizontally, or vertically with the flap by default in the closed position.

Spring type check valves have very strong springs and can significantly reduce the water flow - especially when used with smaller pumps (e.g. under 1HP), while with flap types the resistance to the water flow is negligible.

The term 'ball-valve' is usually used for a tap because inside they have a ball with a hole for the water to pass through.

It would be inaccurate to assume that all other quality brands of pumps other than Hayward are not equipped with 'no flow' protection. That said, we have known plenty of Hayward pumps to run dry and seize.

The Emaux valve may be suitable for my situation because in my case to install a vertical valve would take quite some modifications.

I understand that valve has a spring as well, otherwise it would not close the flap I assume ?

My problem isn't that the spring rust, I think it are SS springs, but just a tear from a leaf, or a stone from the sandwash, will prevent the cone from closing completely.

Is that possibility excluded with the flap type valve?

By the way the Peraqua valve in your link looks identical to my Astral valves.

[SwimmingPoolsThailand]

The check valve with the transparent lid does have a spring for the flap but it is not so strong as the springs in the cone type valves.

Distinct advantages of these flap type valves is their ease of servicing, the availability of parts, and the fact that the passage of water is unrestricted whereas the water passage in other types is restricted by having to pass around a cone or a ball.

There are many brands of the 'barrel' type check valves and they all look very similar due also to copying. Do bear in mind that this kind of valve is used in many branches of industry of which swimming pools is probably the least of their application. The parts however, are not always interchangeable and the retaining rings often have threads of a different pitch. The Emaux type is designed exclusively for use in swimming pool situations and while it is available under several brands, they are not copies - Emaux offer their products as 'white label' to large distributors and other pool equipment manufacturers.

[Anthony5]

The check valve with the transparent lid does have a spring for the flap but it is not so strong as the springs in the cone type valves.

Distinct advantages of these flap type valves is their ease of servicing, the availability of parts, and the fact that the passage of water is unrestricted whereas the water passage in other types is restricted by having to pass around a cone or a ball.

There are many brands of the 'barrel' type check valves and they all look very similar due also to copying. Do bear in mind that this kind of valve is used in many branches of industry of which swimming pools is probably the least of their application. The parts however, are not always interchangeable and the retaining rings often have threads of a different pitch. The Emaux type is designed exclusively for use in swimming pool situations and while it is available under several brands, they are not copies - Emaux offer their products as 'white label' to large distributors and other pool equipment manufacturers.

Would this kind of valve reduce the possibility of having debris preventing the flap from completely closing?

[SwimmingPoolsThailand]

There are clearly fewer cumbersome parts in the Emaux type check valve that can restrict flow and/or entrap debris but of course it cannot be fully ruled out. Regular maintenance and checking of pool systems ensures that problems are avoided before they happen. We have seen many barrel-type cone check valves with debris stuck in the springs and cones. Such check valves are often the source of water flow problems but few people think of looking there first before calling their pool specialist.

With the advent of quality, self-priming pumps, such as Hayward, and Emaux, for example, the merits of check valves on the suction side are debatable, especially if the pump is located reasonably close to the swimming pool or balance tank water and not too high above it.

Too many restrictions such as check valves and elbow bends in the piping can significantly reduce the volume and velocity of the water, often requiring a pump of an additional 0.5HP more even for a small pool up to , say, 10 x 4m. Likewise, unless pumps are located below ground level and below the water line, even the use of check valves in the return system may not be 100% necessary. Check valves are certainly required in multiple pump set ups, but that is for a different reason.