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Old 05-08-2012, 11:53   #1
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submersible vs non-submersible bilge pump

I need to replace the bilge pump on my '84 Ericson 38. Currently it's a non-submersible pump mounted just below the sink in the galley. I don't seem to see much in the way of new non-submersible pumps on the market or even articles discussing/reviewing non-submersible pumps.

Is there a reason these non-submersible pumps seem to be less popular? Should I stick with a non-submersible since its whats already there, or in the interest of having an easy to find replacement in the future would a submersible pump be a better choice?

If I do end up sticking with a non-submersible are can anyone direct me to some reviews/favorite models?

Thanks,

Matt.
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Old 05-08-2012, 11:59   #2
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Re: submersible vs non-submersible bilge pump

Submersible pumps are typically centrifugal pumps, which use spinning vanes, similar to the compressor blades of a jet engine, as the impeller. This is a very quick way of ridding water from your bilge. The downside to centrifugal pumps is that the vanes must be submerged for them to work.

Non-submersible are displacement pumps because they can "gulp" either air or water. In other words they can grab individual units of air or water...similar to a piston engine that has a chamber an inlet valve and and outlet valve, or something similar. Non-submersible pumps, for the same horsepower are slower. They also tend to be more expensive because of their complexity.

If you have a place in the very bottom of your bilge where all the water collects and there is room for a centrifugal pump, then I would go that route. If there is no room where the water collects, then go with a displacement pump. Remember to put a strainer at the end of the hose.

Some people have both where the vane pump is not normally used except for emergencies. If you start taking on a large amount of water, the centrifugal pump will have a better chance of keeping up with the flooding, where you placed it at the lowest point in the bilge that you could fit it. The displacement pump would be used for removing that last little bit of annoying water in the bilge.
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Old 05-08-2012, 13:13   #3
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Re: submersible vs non-submersible bilge pump

the reason they are not 'popular' is that they are vastly more expensive.

Also: "Assfortress" :? lmfao
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Old 05-08-2012, 13:16   #4
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Re: submersible vs non-submersible bilge pump

I'd be interested in reading some reviews of whats out there... all I've come across (in places like Practical Sailor) are comparisons of the submersible models. Any links would be greatly appreciated!

xymotic: why do you prefer them?
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Old 05-08-2012, 13:32   #5
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Re: submersible vs non-submersible bilge pump

I think the more popular brands of the vane pumps are pretty much the same, Attwood, Rule and Shure. No bilge pump in my experience will last a long time and I have gone through a lot of bilge pumps. The seals eventually leak destroying the motor.

You want a pump that is going to be able to kick butt when needed, which if it comes down to one type or the other I would pick a vane pump. Displacement pumps are good for scouring but not so good for removing water at a high rate.

Also, don't trust the rating (GPH rate). All the rating means is no pressure head on the pump. Meaning there is no water being pumped up hill or through any hose for that matter.
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Old 05-08-2012, 14:32   #6
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Re: submersible vs non-submersible bilge pump

Put 3 ft of water in your bilge, stick your head thru the floor hatch, and try to service the submersible while imagining the boat is taking on water.

Now service the attached strainer on the belt driven pump, which is closer to sitting eye level, while you work comfortably on the salon floor.

IMO, stick with the belt driven.
As to cost, my ITT jabscos are 14 yrs old, in the same period, I know boats which have had submersible replaced 3 times.
Jus sayin.
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Old 05-08-2012, 14:34   #7
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Re: submersible vs non-submersible bilge pump

The bilge in my Ericson38 was such that installing a large high capacity pump would not work very well the pump had to go in one part of the grid area and the float in another which caused the pump to drain one while the others still had water in them running pump dry I was never happy with either pump set up(centrifugal or vane) the hose under the grid to the bilge was to small and would require wrecking the sole to access to change only to have problem mentioned above so I had to be satisfied with small capacity pump
I made sure my manual pump was flushed often and in good working order and always remembered this saying " There is no better bilge pump than a scared man with a bucket"
Make sure you get spare parts for vane type it will burn up vanes at some point or wear out Note I ended with a centrifugal pump with relay to help speed of pump also!
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Old 05-08-2012, 14:47   #8
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Re: submersible vs non-submersible bilge pump

A Rule 2000 is going to be faster and have more endurance than a bucket brigade out the companionway.

There are fully automatic bilge pumps in case float switches are a problem.
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Old 05-08-2012, 14:53   #9
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Re: submersible vs non-submersible bilge pump

my 35mII has 2 pumps--one hiding in a place necessary for emergency use--2200gph with flapper switch--and one fully automatic 1100 gph under sole near the water filter for engine. the rule fully automatic pump works great and does the job-- when needed, the other--i think is abaft the engine--kicks in and pumps boat dry.
what ever you have, make sure you do not have to work on it when the chips are down--you WILL sink.... check em and rewire them if needed before you go out on a passage. check the float switch and have a spare or 2, and make sure primary is good --you can never have enough pumps or line.
a non submersible may be just the ticket for emergency, tertiary, use.
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Old 05-08-2012, 15:30   #10
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Re: submersible vs non-submersible bilge pump

I recommend 3 Pumps.
An electric Primary diaphragm, Secondary electric centrifugal, and a manual Tertiary* diaphragm pump.

Where two electric pumps are installed**, the smaller capacity non-submersible diaphragm pump is usually tasked for primary use, pumping small amounts of normal ingress (mast drainage, packing gland lubrication & etc); whilst a larger capacity submersible vane type centrifugal pump is tasked with emergency (tertiary*) tasks.

*Tertiary usually relates to a “third order” (behind primary & secondary), though is often misused to describe “final”.

** See also ➥ http://www.docksidereports.com/bilge_water_blues.htm
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Old 05-08-2012, 16:21   #11
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Re: submersible vs non-submersible bilge pump

Ive used all 3 types, and the one I know I can depend on is my manual hand pump !! I ck it everyday! and will even put water in the bilge to make sure it and my other pumps work !! Our Colvin was so dry we never knew if our pumps worked or not ! So we cked them at least once a week by tripping the float switchs, and such ! just our 2 cents
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Old 05-08-2012, 18:07   #12
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Re: submersible vs non-submersible bilge pump

Quote:
Originally Posted by Blue Stocking View Post
Put 3 ft of water in your bilge, stick your head thru the floor hatch, and try to service the submersible while imagining the boat is taking on water.

Now service the attached strainer on the belt driven pump, which is closer to sitting eye level, while you work comfortably on the salon floor.

IMO, stick with the belt driven.
As to cost, my ITT jabscos are 14 yrs old, in the same period, I know boats which have had submersible replaced 3 times.
Jus sayin.
^^^^^ That's why

Also, after 14 years, you can fix it the others are pretty much disposable.
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Old 05-08-2012, 18:35   #13
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Re: submersible vs non-submersible bilge pump

ON an Ericson 38 you dont have most of these options due to grid system!
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Old 05-08-2012, 18:59   #14
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Re: submersible vs non-submersible bilge pump

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Originally Posted by sartorst View Post
ON an Ericson 38 you dont have most of these options due to grid system!
Once water starts entering the hull in quantities a high capacity pump is there to handle, the grid partitions will quickly be underwater. Seems to me you need a high capacity pump (several, if going offshore) regardless of the details of how your bilge is configured.

If need be, surely you can have a plug-in, 'wandering' suction hose to enable the same pump to evacuate individual compartments, once you have stemmed the inflow.
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Old 05-08-2012, 19:21   #15
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Re: submersible vs non-submersible bilge pump

Quote:
Originally Posted by GordMay View Post
I recommend 3 Pumps.
An electric Primary diaphragm, Secondary electric centrifugal, and a manual Tertiary* diaphragm pump.

Where two electric pumps are installed**, the smaller capacity non-submersible diaphragm pump is usually tasked for primary use, pumping small amounts of normal ingress (mast drainage, packing gland lubrication & etc); whilst a larger capacity submersible vane type centrifugal pump is tasked with emergency (tertiary*) tasks.

*Tertiary usually relates to a “third order” (behind primary & secondary), though is often misused to describe “final”.

** See also ➥ Bilge Water Blues: Boat Maintenance/Repairs
I recommend one more...... a centrifugal that you can place anywhere in the boat. When you are healed and taking on water from somewhere, it may not always get to your bilge pump.

Cheers
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