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Old 20-06-2006, 14:54   #1
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Bilge pumps

On my boat I have a 750 gal Rule 3 way switch (auto & manual) bilge pump. I want to add a backup 1000 gal pump and in addition a sump box for the galley & head sinks which has a 500 gal pump...all 3 pumps are on 3 way switches. I want to run the lines towareds the stern where the bilge line out (about waterline) is located and then "T" them all into my bilge out hose. If I put check valves in the lines before the "T" will this system work? My concern is that the water may just be pumped back down the line and into the bilge with this method.

Thanks in advance.... Gary
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Old 20-06-2006, 15:11   #2
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An anti siphon loop is a good idea for each line and if you do create a manifold with a single discharge it is rather unlikely that one pump will feeed pump back up to another.. but check valves placed at the manifold would prevent backflow I think.

If you want to keep your bilge dry you would need to place the check valve as close to the lower point. If not, your pump will take the water and send up the hose... when the float switch or the manual switch is on.... then when off whatever remains in the hose might return back down into the bilge... so you could get the pump to continue cycling as it fills the hose and gravity then returns the water back to the bilge.

Sounds weird eh?

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Old 20-06-2006, 15:29   #3
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With the check valve water on the otherside of the valve can't come back but it is nice if it can drain and not stay stagnant inside the hose.

Stagnant bilge water might make more problems inside the hose than back in the bilge. Located beyond the highest point plus a little bit will prevent back flow and drain the hose both directions. Bilges are easier to clean than hoses. The water below the high point towards the bilge really needs to come out some place.

The anti siphon loop is still required so you can't escape the problem. The anti siphon is in case the check valve should become clogged open. You don't want the whole thing based on one check valve always working. Making the loop close to the blige means the water runs downhill out the through hull and reduces the amount of water that flows backwards.

I would make an anti siphon for each line and a check valve for each such that the manifold drains by gravity. Make sure you have a cleanout as the monifold is going to be the place where you might need to service a clog.
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Old 20-06-2006, 16:08   #4
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The main difficulty that I could forsee is that if you get a single failure or blockage in your system then it may not work.
Is it possible to plumb all three pumps to separate thru hulls?
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Old 20-06-2006, 16:39   #5
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No check Valves.

From
ITT Jabsco Industries (Jabsco Pumps): http://www.jabsco.com/rule/faq.asp
”As submersible pumps create very little discharge pressure, they may not be able to overcome the resistance or weight of the column of water or weight of the check valve flapper or poppet itself. The pump may therefore have an airlocked condition.”

From David Pascoe’s “All About Bilge Pumps” (as cited by Rick): http://www.yachtsurvey.com/bilge_pumps.htm
”...Syphon breaks and check valves are notoriously unreliable because of their tendency to get clogged...”

I think Pascoe also addresses multiple Pump discharge outlet manifolds.
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Old 21-06-2006, 06:07   #6
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I use a small bilge pump in my engine compartment which is usually quite dry as I have a PSS dripless shaft seal. But when I do get water in there the little Rule pump can remove the water and the run is 20' ± to the transom located thru hull discharge. I also have a small check valve located a foot or so from the pump.

Before installing the check valve, the pump would remove the water... then when it shut off, the water in the 20' hose would drain back into the bilge which would mean that I could never remove more than the amount of water volume of the hose.

This is not longer the case. I changed to a small Automatic Rule pump which does not use a float switch but comes on and pumps for every few minutes and shuts off almost immediately if there is no water. I like not using a float switch and this is pretty low draw, but I have no idea of how reliable this system is. So far so good. But the jury is still out.

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Old 21-06-2006, 12:22   #7
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check valve

My only attempt at getting a check valve to work on the OUTPUT side of the self contained bilge pumps didn't fly. The Rule3000 pump I HAD would not PUSH the gate valve open. I've since gone to a remote mounted JABSCO diagrapham pump. The new bilge pickup contains a check valve and works like a champ. In no small part I figure because now it's located on the inlet side of the pump where it is now opened with suction rather than on the output side where it's attemting to be opened with water pressure from the pump.

So I guess I'm saying that I doubt your scheme will work.

Best of luck

Randy Cape Dory 25D
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Old 21-06-2006, 16:55   #8
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I am going to have to completely overhaul the bilge pumping system on Insatiable She currently has no electrical bilge pumps and 2 rather dodgy manual bilge pumps (Whale Gusher-10). I am hoping that new seal kits on the Whale Gushers will bring them up to scratch, but if not, does anyone have a recommendation for a good reliable manual bilge pump?

I also plan on installing 2 electric bilge pumps.

I was wondering; would it be foolish to T each electric bilge pump into a manual bilge pump line? I kinda have a thing about not making new holes in the hull unless I absolutely have to!
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Old 21-06-2006, 23:55   #9
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Through the stern?

To Weyalan
Could you run the outlet through the stern?
The other place it can be nice to have a bilge pump outlet is in the cockpit. Sounds strange but if you can't see it you know all is well!
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Old 22-06-2006, 01:20   #10
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You could drill a hole slightly lower down than were water comes in, so the water can run back out.
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Old 22-06-2006, 04:40   #11
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Some good Online References:

All About Bilge Pumps ~ by David Pascoe
http://www.yachtsurvey.com/bilge_pumps.htm

Bilgewater Blues ~ by David Pascoe
http://www.docksidereports.com/bilge_water_blues.htm

20 Electric Bilge Pumps Tested (Powerboat Reports/Practical Sailor):
http://www.powerboat-reports.com/sample/bilge.html

Choosing and Installing Bilge Pumps:
http://seagrant.uaf.edu/bookstore/bo...ilge-pumps.pdf

Hysteresis in Your Bilge? ~ by Robert J. Scott
http://www.practical-sailor.com/news...hysteresis.pdf

OYRA - Minimum Offshore Requirements:
http://www.yra.org/charter-associati...nequipment.pdf

Bilge Pumps:First and Last Lines of Defense ~ by Tom Wood
http://www.sailnet.com/collections/c...at=Equipment&C

Installing a Bilge Pump ~ by Don Casey
http://www.boatus.com/boattech/casey/14.htm
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Old 22-06-2006, 12:27   #12
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A portable electric bilge pump of high capacity with a long large diameter discharge hose is a good idea for offshore and emergency use. You can run the hose into the cockpit or overboard though the companionway.

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Old 22-06-2006, 12:54   #13
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Weyalan-
AFAIK the Gusher pumps can be rebuilt for a thousand years with those kits, and they'll outlast the hull around them.<G>

If I wanted a short discharge line for an emergency pump, and didn't plan on sending bilge water through it on a regular basis, I think I'd just take it up to the coachhouse side, or into the cockpit (assuming that had adequate drains for the capacity) and figure in an emergency, that's going to work well enough, and give me visible proof it is working.

Keeping in mind antisiphon loops or a seacock to prevent backflooding.
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Old 25-06-2006, 13:45   #14
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Bilge Pumps

Thanks all... I like the suggestion of a separate thru hull for the back up line. Although I cringe at a hole in the hull this option makes good sense. It is stand alone and will guard your bilge 24/7 even when you are off boat. I nearly lost my boat last year because the stuffing box nut loosened and water entered up to floor boards. My random return to the boat after some shore supplies was all that saved her. The rule pump I had in there did not work....except after reaching down and giving it a good shake, and it started pumping. Back up ...back up... back up...

Gary
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Old 25-06-2006, 13:57   #15
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Gary,

I had almost the same thing last year. Stuffing box was leaking badly from a missaligned coupling. The Rule pump died, water to the floor boards as fireworks from 4th of July were going off. Hand pumped all night every few hours. Sometimes when you learn the lesson you take the medicine.

Wire the backup on it's own circuit too in case the regular pump shorts and blows the breaker. Wire the back up a few inches above the regular pump in case you get a big gulp or the regualr pump fails or can't take the load for any one of a lot of reasons. A friend also wired a light at the helm that comes on when the bilge pump is operating. If it does not go off quickly you need to tend to something.
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