Quote:
Originally Posted by Raoul5Duke  I am reworking my plumbing, trying to make it more efficient/neater. I installed a check valve and now it seems like I am not getting nearly the flow I once was. I added maybe 1 additional 90 bend from what I had before and a gate valve so I don't think that would have caused this much head loss. Any thoughts? |
First, as long as the inlet and outlet of the valve is the same or larger than the line, it should not be too restrictive at all.
However make sure you are using a flap-type check valve for aquarium use. Most check valves you see that looks similar at Home Depot or Lowe's are "spring type" valves. Though these look very similar in external design, internally, they are very different. The latter ones are used or home application like garden sprinklers and shower heads where supply of water is at very high pressure. They will completely restrict the flow of an aquarium pump as the springs will push back the water and fight the pump.
A proper flap-type check-valve for aquariums have a small flap inside, similar to traditional toilet tanks... They are not restrictive and are not spring loaded but are designed to close when the water flow is reversed (ie siphon effect).
I hope that helps...
BTW: like most people will say though, that using a large enough sump with properly designed overflow box, and return lines placed properly at shallow depths in the tank will eliminate the need for these check valves as total water drained down from it will still hold the water within the sump...
(Which I feel is a better design fish tank anyway!!)