I work for a water well company and we have 1 1/4 inch spring check valves that go on our pumps. Would they be ok to use? I guess I would have to check the temperature rating on them.
Two things to look for in a check valve to be used on hydronics. The "pop" pressure that is required to open the check. For hydronics usually a 1/2 psi. Remember a small hydronic circ may only provide a couple lbs delta P. Also the Cv of the valve, this is the gpm flow thru the valve with a 1 psi drop. Look at the submittal sheet above from Apollo to see how those numbers look on a hydronic type check.
If you pull the submittal for a swing check you will see a much higher cv. The problem with a high Cv if you operate with low flow rates, or variable speed circulators, the swing will not open completely.
The spring check above also has a soft seat, so it is noise free when the flow stops. It only opens 1/4 of an inch or so, and the spring closes it, not the pressure in the system. It also has a tapered cone, much friendlier to flow. This check is also called "bubble free" meaning 100% shut off.
A swing check requires back pressure to seal it off, that not what happens when a circ pump stops, there is no back pressure in a closed loop hydronic system, when the circ pump stops you have the static pressure the same on both sides of the check. Much different from a well, sump, or lift pump where the column of water above closes and seals the check.
No doubt swing checks are used and can do some duty in hydronics, but they are not the correct valve for the job. just saying
Look at the checks that are included in most hydronic circs now, same as the guts of the Apollo above, 1/2 lb. pop, tapered cone, soft seal, Neopryl brand.
Some brands of swing checks can be mounted in either position, not all, depends on the construction of the valve, and the application.
