Return pump priming needed?

[mark]

Originally Posted by Eb0la11

I have estimated this to be around 20-25G and so that'd mean 15-20G on my floor if the power did go out.

as check valves aren't 100% (they'll get debris or buildup on the seats that will allow them to leak) that could be quite the mess.

Anyway you could raise you return?

[hillegom]

Originally Posted by mark

as check valves aren't 100% (they'll get debris or buildup on the seats that will allow them to leak) that could be quite the mess.

Anyway you could raise you return?

+1
I would not rely on a check valve. Remember Murphys law

[Eb0la11]

My return holes are drilled at the highest point possible. Ive said it my build thread that 15-20G on my floor wouldnt really be the end of the world. Im in a basement thats unfinished so it wouldnt really do much damage. I already had some from my FW tank leak when one of my o-rings wasnt tight on my pumps when I moved to this new place. No biggie, but itd be nice to have a flood proof tank.

I got a backup plan anyways if this check valve doesnt work by the end of tomorrow for an emergency empty reservoir that I could plumb off my sump through the, right now, plugged holes drilled in the back that are a bit above my chambers.

[ALBERTA REEF]

I took a look at your thread build. I think your pump is too small for your plumming. My thinking your flow was bare mine from the outlet. By adding the check valve choked it some more. Try turning off three of your return feeds and see what happens.There is a head chart on Reef Central.

http://www.reefcentral.com/calc/hlc2.php

[Eb0la11]

Yeah it was a spring loaded check valve that required too much force than my pump could supply to open... I've replaced it with a swing type check valve that needs a whole lot less force to swing open.

I tried the closing 3 valves to my returns and it still didnt work, but thats all beside the point now since my system works well, at least the return aspect so far.

Now I am fine tuning my drain. I have to re-plumb my 'T' off to my refugium and thats where Im at now. I got the parts but gotta cut into my pipe a bit to fix it.

My next problem after that is my needle wheel pump for some reason is not starting when I plug it in. Ive tested it before and its worked everytime so this is bizarre why it wont work now. Its been a bit finicky at worst but hasnt ever plain not started so Im not sure whats wrong.

Suggestions?

[ALBERTA REEF]

Is the needle wheel pump is used for the return, usual they are used for skimmers. I still think your pump is still to small of a head height. It runs but does not have enough to get it there. A vane tip pump is better for returns. Hear is a though I have a mag 24 (2400gph) we can plum in to see.

[banditpowdercoat]

Originally Posted by ALBERTA REEF

I took a look at your thread build. I think your pump is too small for your plumming. My thinking your flow was bare mine from the outlet. By adding the check valve choked it some more. Try turning off three of your return feeds and see what happens.There is a head chart on Reef Central.

http://www.reefcentral.com/calc/hlc2.php

Adding outlets does nothing to increase head pressure. Neither does pipe size. A 6" diam pipe will have the same head pressure as a 1" pipe of same height.

[whatcaneyedo]

Originally Posted by banditpowdercoat

Adding outlets does nothing to increase head pressure. Neither does pipe size. A 6" diam pipe will have the same head pressure as a 1" pipe of same height.

Thats quite the statement and contradicts everything I've seen and read. Do you have any sources to back it up?

[banditpowdercoat]

Ya, Any plumbing manual. Head pressure is only the verticle height. It does not matter the diameter of the pipe. Now, when talking Flow restriction, that goes by pipe diameter, But if you have a 1" pump outlet, Doesnt matter if its 1" all the way up, or if it expands to a 6" pipe, the head pressure at the pump will be the same. GPM flow may be affected by the smaller pipe and friction loss, but not head pressure.


Think of it this way, Head pressure is in PSI, right? So, take a 1"x1" column of water 6' high. It has X head pressure. Now take a 6" pipe, Head pressure is still measured in PSI. Yes, the pipe is larger, but you only take a 1"x1" section of the pipe for figuring head pressure.


Or, take my fish tank, 150g, 5'x2'x2' Its 2' high, does not matter that the tank is 5' long, or 50' long, the pressure(PSI) at the bottom of the tank is the same, Its dependant on height, not LxW


Hope that helps

[whatcaneyedo]

So your argument is simply that we were using the wrong terms, calling everything head pressure where as theres two different concepts: head pressure and flow restriction. Like the way everyone calls all sea slugs nudibranches... Never mind then.

I blame Delbeek and Sprung for mixing me up. "Head pressure refers not only to the vertical distance a pump must push the water, but also any resistance to flow created by pipes, fittings, and valves." The Reef Aquarium Vol 3