2 pumps on 1 bulkhead? Ok or no?

Delphinus · #1 08-16-2010, 06:11 AM

I have a bad feeling I won't like the answer to this, but I'm gonna pose the question anyhow in an effort to be optimistic.

Can I put a "T" on a bulkhead and run two pumps off the same bulkhead?

Or will the pumps "fight" each other too much for suction?

I really would prefer to avoid drilling for a second bulkhead, not that I don't mind drilling the glass but more out of space considerations, I don't really have a spot for a second bulkhead, short of patching over the existing hole and redrilling both holes. The whole idea just totally deflates my balloon. I'm tempted to try it and see what happens but the cost of 2" PVC bits (I've got a kick arse 2" true-union valve for blocking off the bulkhead side so I can do things like PumpMaintenance(tm) down the road, but the sucker is HUUUUUGE .. and .. um .. expensive. So I don't want to screw this up and have to buy a new one.)

MitchM · #2 08-16-2010, 10:25 AM

What pumps Tony?

Mitch

intarsiabox · #3 08-16-2010, 11:59 AM

Will likely get cavitation in your pumps but you may be able to throttle the discharge side down enough that it will work. If you get a gravelly sound out of your pump(s) when you turn them on just close the discharge valves off until it goes away and then see if you are still getting enough output for your needs.

golf nut · #4 08-16-2010, 12:59 PM

Depends on the bulkhead size and the pump inlet size. what do you have?

JonT · #5 08-16-2010, 01:11 PM

Quote:

Originally Posted by intarsiabox

Will likely get cavitation in your pumps but you may be able to throttle the discharge side down enough that it will work. If you get a gravelly sound out of your pump(s) when you turn them on just close the discharge valves off until it goes away and then see if you are still getting enough output for your needs.

This is the most likely result.

Is this a CL? Trying to figure out what your up to, and trying to do? I am sure that this may have been the easiest way, but this hobby is full of DIY'ers, and I am sure we can come up with Plan B-Z for you

amoreira · #6 08-16-2010, 01:48 PM

Cavitation is rarely a concern for small pump a used for aquariums. Also Putting pumps in parallel does not reduce the suction head requirements (NPSHR). So go for it.

Delphinus · #7 08-16-2010, 06:40 PM

One pump is a Reeflo Dart for sump return, the other would be a GenX/Mak4 (assuming it still works, it should, it's just been shelved a few years), which would drive the skimmer (beckett). The GenX should be better able to push against head pressure and wouldn't be throttled; the Dart will likely be throttled but I'm not sure how much will be needed until I fill the tank and see how things settle out.

The Dart has a 2" inlet port and the bulkhead is 2". The GenX on the other hand has a 3/4" inlet port.

My worry is that one pump's suction could be perceived by the other pump much the same as a blockage or throttling on the input side. I know that throttling the outlet side of a pump is copesetic (it's just head pressure); but that throttling the inlet side of a pump is a no-no

so was sort of curious if two pumps pulling out the same pipe could produce a similar effect, or if it just creates a wicked suction into said pipe via the bulkhead...

Thanks for the thoughts..