Swing or spring check valve?

[sundug]

After removing and rebuilding my solar hot water collector I noticed the swing check valve was allowing reverse flow. It's a typical brass swing check like this- Shop AMERICAN VALVE 3/4" Brass Check Valve at Lowes.com
It is installed in a horizontal pipe. I am wanting to install a vacation bypass valve to go around another check valve. Because the present check valve is in a difficult place to get to, and I don't have the room there to bypass it, I was just going to disable it. However, all the rest of my plumbing is on angle and I see spring check valves that claim they can be installed in horizontal or vertical positions. I assume that means they can also be installed on a 45 degree angle. True? Another concern is my closed loop is driven by a 21-year-old 10 watt photovoltaic panel, and I'm wondering how much back pressure a spring check will provide or a swing check on a 45 degree angle. Does anyone have any experience in this area? Thanks, Doug

 

[speedbump]

I'm not with you on:

my closed loop is driven by a 21-year-old 10 watt photovoltaic panel,

Is the panel driving a pump of some kind?

Swing checks are subject to leaking if there is no pressure pushing the gate closed. Spring checks aren't the most dependable without pressure when horizontal.

 

[sundug]

I'm not with you on:
Is the panel driving a pump of some kind?

Swing checks are subject to leaking if there is no pressure pushing the gate closed. Spring checks aren't the most dependable without pressure when horizontal.

Yes, the PV panel directly drives a small circulator pump. Low pressure, so I want to know which check valve will work best on a 45* angle, and have the least flow restriction. Thanks, Sundug

 

[Mr_David]

Swing checks tend to fail because of the minerals from the water binding to the seating surface and the hinge pivot. The smaller 3/4 spring check valves often now are made with plastic pistons ( less likely to attract mineral deposits) and the springs are very light on pressure.

Sorry I don't have any real stats or specification to tell you which would be better.

Some of the new Grunfros pumps have a plastic spring check inserted into the flanged end of the pump and is easily removed or replaced.