scupper valve / tee to pumps

(mdan) · (mdan) **Join Date: Apr 2003** 05-05-2004, 2:08 PM

can I tee off the scupper valve? I currently run a scupper to a single pump filling both tanks etc. I would like to run a tee to two seperate pumps of the scupper, one to the left side of the engine and right side. Will this work, I cant fit a manifold in the tight area of the valve so I was thinking of a tee or a y adapter? let me know soon, I really dont want to cut another hole in the bottom of the boat for a dedicated fill pump.

Mike
2001 san

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 05-05-2004, 3:38 PM

I am not sure what you mean by "scupper", but if you mean the through hull fitting, the answer is "maybe".

If both pumps are "positive displacement" type pumps then it won't be any problem. If you have the more common centrifugal pump it will depend on how far below the waterline the pumps are.

The centrifugal pump has to be below the waterline in order for it to prime. As long as it gets a prime it will suck a little, at least enough to get a reasonable flow of water going. If you have two pumps on the same line, however, the suction from one pump will want to draw air back through the other pump. Once this air reaches the pump it will drastically reduce the flow.

In general, you would be much better off to run each pump to its own through hull.

Rod

(mdan) · (mdan) **Join Date: Apr 2003** 05-05-2004, 5:25 PM

hence the newer three hole scupper through hulls on all the 2004 teams etc. thanks, looks like I will be drilling.

(flsurflover) · (flsurflover) **Join Date: Aug 2003** 05-06-2004, 7:04 AM

A scupper is scoop-type thu-hull, instead of the basic mushroom-type. If you fill while moving and use a large diameter thru-hull, seems like they would both prime easily because of the pressure from the scoop. You will need valves on both pumps anyway, so if you only want to use one pump, you would have the other pump's valve off so no air would be sucked through it.

Seems like testing this would only cost you a T fitting, and you could always put in another thru-hull and pump if you didn't like the performance.? And like Rod said, keep the pumps as low as possible.

Or buy Simers.

(mdan) · (mdan) **Join Date: Apr 2003** 05-06-2004, 11:23 AM

Collin,
I have two simer pumps, three jabsco ballast puppies etc. I have found that the cheaper areator pumps, attwood's 750 work better for filling my tanks,bags. The simers and jabsco's are harder on the battery, and sometimes I would leave them on, and the jabsco's would do its rundry protection mode and not work for 20minutes.
I can tell you stories about the jabsco's, better luck with the simer's though. but for now I am going with the areators.

Mike
2001 san