Swing Check Valve

[mdragon]

I'm installing a recirculation line in my home and did all my piping before receiving my Grundfos pump. I installed a swing check valve on the return line going into the cold side of the hot water heater. There is no water flowing in the direction towards the water heater (final connection has not been made). I have cold water going through the swing check valve in the opposite direction of the arrow on the valve. My question is does that valve need water pressure from both sides in order for it to work correctly? Thanks for all responses in advance.

[Sylvan Tieger]

Check valve especially imported cheap ones do not prevent back flow.

This is one of the many reasons they are not considered back flow protection.