Another Plumbing Question

I'm setting up a 180 gal reef and was wondering what size bulkhead to put on the sump. It's for the inlet side of the return pump which is an Iwaki MD70RLT, it has 1 inch MPT inlet/outlet. Is it necessary for the bulkhead and ball valve on the inlet side of the pump to actually be bigger than 1 inch to reduce friction. Also the outlet side of the pump gets split to two 3/4 inch returns. Does it make any difference how close to or far from the pump outlet the split is made?

TIA for your help.
Ted

 

Ted,
If you look inside the pvc valve you can see that the inside diameter doesn't get any smaller than a regular piece of 1 inch pvc pipe. This means there are no flow restrictions and it is not necessary to make it a larger size.
"Does it make any difference how close to or far from the pump outlet the split is made?"
Unless we are talking about a distance of more than 10 feet. I do not think it will matter one way or the other..

Jim

 

Ted,
After reading your questions again, I would have to ask you what are the pump specs? If the flow rate of the pump exceeds the gravity drain rate of 1" pipe, then you might want to increase the size of the pipe or go with two 1" drain lines.

Jim

 

Here's a link to the specs on the pump:

http://www.marinedepot.com/aquarium_pumps_iwaki_japanese_american_md5570100_information.asp?CartId=
Iwaki Aquarium Water Pump MD55RLT/MD70RLXT/MD100RLT Information - Marine Depot - Marine and Reef Aquarium Super Store

I'm a bit confused, somewhere I got the idea that the drain rate for 1" pipe was only 600 gph but I am seeing a lot of pumps rated up to 2000 gph that have 1" inlets. Am I supposed to put a bushing on the inlet to increase the size of the pipe going into it?


btw The tank is an AGA 180gal (72x24x24) with two corner overflows and two 3/4 inch returns.

Sorry if these seem like silly questions, I've always used submersible pumps in the past and never really thought much about the size of the inlet (or the outlet for that matter). This is the first time I've done anything like this and want to get it right.

TIA
Ted

 

Ted,
The difference is the 1" pipe is on the suction side of a pump, so the flow rates will be greater than the flow rate of water that is gravity draining through the same size pipe.
The pump is creating a low pressure area on the suction side of the pump, so it will flow very fast as long as you have enough suction head ( water column height )
In summary as long as the two 3/4" overflows can gravity drain 35 gpm to your sump then you can go with the 35 gpm pump. You always want your drains to be able to handle more than your pump is rated for, this way you do not overflow your tank.
And you do not have to throttle the discharge of the pump....

Jim


P.S. I am hoping someone with a reference to a chart will chime in here and point out the gravity drain rates for water through different size pipes. I am unable at the moment to find one

 

If I read your initial post and post #4 correctly, the 3/4 pipes are the returns from your pump to the tank. That should be fine, the pump will handle that nicely. What do you have in terms of an overflow from the tank to your sump? That is where you could run into a problem with gravity and the pump outpacing the drain.

Mike

 

The tank has this MegaFlow kit in each of the back corners:

http://www.all-glass.com/products/aquariums/megaflow.shtml
All-Glass Aquarium - MegaFlow™ Overflow

I used a 1"x1 1/4" barbed to slip adapter elbow on each one and ran two seperate 1 1/4" pvc lines to the sump for the overflows. (two seperate lines from the tank to the sump)

The tank is supposed to handle 1200gph. The pump is rated at 1500gph at 4 feet and by looking at the flow curve it looks like it's just over 1200gph at 8 feet. I'm not really sure what the total head will be when it's all set up though. I thought I could put a diverter valve on the outlet side of the pump and direct the extra flow back to the sump if I had to.

The sump is a 150 gal rubbermaid stock tank, it's in the garage on the oppisite side of the wall from the display tank. I'm open to suggestions, nothing is really etched in stone yet although I do have the overflow drains installed as I discribed. I haven't even bought the pump yet but it seemed like a good choice.

TIA for all your help
Ted