CH non return valve

[Paul]

As a result of fitting an UFH circuit to my fathers old single pipe central heating system, I have a requirement for a low loss non return valve capable of withstanding CH water temperatures.

A quick dig around on the net last night found lots rated at 65 deg C with occasional use at 90 deg C, can anyone recommend a make of such a thing that is rated at a higher temperature than 65 deg C ??

Thanks,

Paul.

[John Stumbles]

I don't know what you've been looking at but if you're planning to fit any normal single check valve into a CH system you're in for a performance like junior's first attempt at playing a brass instrument - the springs in check valves are just way too much for CH pumps to deal with and you'll giet vibrations as the pump opens the valve and it springs back again. What you can do however is to find a type which you can dismantle (i.e ideally the 'C' shaped spring holding the gubbins in protrudes slightly into the valve so you can pull it out with long-nosed pliers) and remove the spring which returns the valve to the shut position, then mantle it again giving you a valve which will shut off against reverse flow but has very little resistance.

Alternatively BES have various purpose-made gravity and swing valves.