Two bilge pumps on same output hose?

Igofaster

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Jul 25, 2006
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I am adding another bilge pump because my 87 bayliner capri leaks a little. The current bilge pump sits up a inch or so and has its own internal float switch, so it does not catch the water that is below that pump. There is a place to put another pump in to collect that water. My question is can I run the second pump to the current bilge output hose with a three way splitter? Or do I have to install a shut off valve in line between the original pump and splitter to prevent it spraying out the original pump when the second pump is turned on? Thanks
 

xtraham

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Jul 20, 2006
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Re: Two bilge pumps on same output hose?

no splitter, run another discharge hose and through haul fitting, each pump needs it's own switch and hose, it never hurts to have 2 pumps but I'd try to find the leak before it gets worse
 

Texasmark

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Re: Two bilge pumps on same output hose?

Interesting question about backflushing. I guess you could run a test before you do the installation. If there is nothing but an impeller in the pumps flow line (probably is the case), the back pressure could easily spin it and the little motor in reverse and leak water out the inlet. A check valve like you would use on the water supply to your house might work with a little pressure drop.

The other problem is that these are centrifugal pumps whose output drops as a function of back pressure. If you try to pump two into the same hose, the back pressure may be sufficient to cause you only a slight improvement over a single because when one has a good load of water to pump, the water volume is real good coming out of the spiggot.

The best solution is as xtra said and that's just add a second circuit. It's no biggie to bore another hole in the boat and install a bulkhead adapter for the second outlet. Marine industrial supply or marine dealer should easily have the adapter and hose and all.

Mark
 

03TB

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Nov 17, 2006
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Re: Two bilge pumps on same output hose?

I wouldnt worry about the second bilge pump right now, and first take care of that leak your talking about. A second bilge pump is not going to matter when that leak gets bigger and 2 bilge pumps cant keep up. Fix the leak, then if your still inclinded to, add a second bilge pump.

Good luck with it and let us know how it turns out.

Doug
 

Igofaster

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Re: Two bilge pumps on same output hose?

How do I find out where the leak is coming from? I have allready sealed the outer seal on the outdrive transome with 5200 and that did not work. I have looked at the hull and there are some small chips showing the inner fiberglass, Could that be where its leaking? Thanks
 

Igofaster

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Re: Two bilge pumps on same output hose?

And I want to run one pump at a time, The second pump Will be for the water below the original pump. I would turn the on/off valve inline to the original pump off when I wanted to use just one pump, But in an emergency, Have it possible to run two pumps out of one outlet hole, I dont really want to drill another big hole in the hull.
 

Texasmark

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Re: Two bilge pumps on same output hose?

Well pilgrim, if you want to run them in series, then have at it. Lot different than in parallel. d:)

Mark
 

Reel Poor

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Re: Two bilge pumps on same output hose?

The diameter of your existing thru hull fitting is a restrictor for pumping water out of your boat. Whether you use one pump or ten pumps that outlet is only going to allow so much water to exit. Your plan with the valve would work but will only give you a false sence of added saftey.

There is no reason not to drill the second hole in your boat and install the second pump properly. It's a common practice and will not take away from the boat.
 

imported_Curmudgeon

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496
Re: Two bilge pumps on same output hose?

I have allready sealed the outer seal on the outdrive transome with 5200 and that did not work.

Hope you never have to replace the outer seal ... :love:
 

MikeV4

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Sep 18, 2006
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Re: Two bilge pumps on same output hose?

Funny replys here:

bore another hole to solve a leak 8)
 

Igofaster

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Re: Two bilge pumps on same output hose?

I put the second pump in with a 3 way splitter and the valve between the original pump and the splitter. Tested it and it works great! With just the second pump on it pumps out good, but when the bilge is flooded the original pump turns on with the second pump on, and pumps water out fast, faster then just one pump, I think the system I made works great!
 

Texasmark

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Re: Two bilge pumps on same output hose?

Ok Igo, you failed to tell us what your final configuration was. Would be considerate if you would share that with us beins we did our best to help you and your feedback will help the next person asking this question. :/

Mark
 

Igofaster

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Re: Two bilge pumps on same output hose?

Texasmark said:
Ok Igo, you failed to tell us what your final configuration was. Would be considerate if you would share that with us beins we did our best to help you and your feedback will help the next person asking this question. :/

Mark


My configuration is: 2 bilge pumps under the engine, The original pump had a single output hose going to it, I cut the hose about half way up and added a 3 way splitter. Then I added the new pump deeper into the bilge to pick up the water that the original pump was not. Then I added a new peice of hose, connected it to the new pump and that hose went to the 3 way splitter. I then added a on/off valve between the original pump and the 3 way splitter to eliminate water flowing back through the original hose when the second pump is turned on. If there is a serious flood, The on/off valve will have to be turned on and the internal float switch will turn on the original pump with the second pump pumping through one output hose. I tested it on the water today and it does keep my bilge pretty dry, I personally like the system I made.
 

Reel Poor

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Re: Two bilge pumps on same output hose?

Did you install a float switch on the pump you added, or is it operated by a manually operated switch.
 

Boatin Bob

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Re: Two bilge pumps on same output hose?

I'm glad that it works for you and you are happy with the outcome but personally I would rather have identical but totally separate systems, I just don't want to have any check valves or splitters or anything else that may go wrong and cause a problem. My current boat has 3 bilge pumps, float switches and output hoses and have nothing in common with each other except that they all do the same job, pump water overboard!
 

Texasmark

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Re: Two bilge pumps on same output hose?

Ok, thanks. So you did install a "check valve" between the pumps. Is it manual, or did you install an electrical solenoid operated with operation of the pumps?

For the record (and answering the question I was wondering about the other day), I had a pump apart just yesterday and there is nothing in there to stop back flushing. The impeller looks like the prop on a Jet Ski (not very big for the size of the hole) and there is nothing else in there.

Thanks for the explanation.
-----------------------

Bob,

Don't know why, but I was thinking about you the other day. Been trying to get my new Avatar pic onto full screen so I can get on the "Lets see your boat" thread but am not there yet. Just remembered you there with your "big" boat that needs 3 pumps (cause it's so big d:) ) and your kids play boat that's bigger than my "family" boat. :%

Later,

Mark
 

Igofaster

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Re: Two bilge pumps on same output hose?

Texasmark said:
Ok, thanks. So you did install a "check valve" between the pumps. Is it manual, or did you install an electrical solenoid operated with operation of the pumps?

For the record (and answering the question I was wondering about the other day), I had a pump apart just yesterday and there is nothing in there to stop back flushing. The impeller looks like the prop on a Jet Ski (not very big for the size of the hole) and there is nothing else in there.

Thanks for the explanation.


The only valve that I installed was a manual on/off valve between the original pump and the 3 way splitter.
 

Boatin Bob

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Re: Two bilge pumps on same output hose?

Igo.....just reread your post again about the valve, sorry I thought it was a check valve but it's clearly a manual valve and it is probably going to be closed most of time? So in the scenario, boat is in the water and is taking on water and no one around, the new bilge pump will auto come on and pump out but what if there is too much water, sounds like the second (original) pump will turn on with it's float switch but can't pump any water out because you aren't there to open the valve, if I understand what you have done?
 

Igofaster

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Jul 25, 2006
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Re: Two bilge pumps on same output hose?

Actually, the original pump has its own internal float switch & will kick on when the bilge has alote of water. The valve is going to be closed most of the time. I now use the new second pump as my main because it picks up more water then the original pump. The original pump is now kind of a back up.
 
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