What type of bilge pump to install?

[Albicelesail]

Well, I have a 20 ft run from the thru hull to the collection point in the bilge. There is approximately a 3ft head. The bilge collection pocket measures 7 in× 7in. x 9in high ( to the floor boards). The maximum bend radius of the tubing is 3 in ( 1 1/8 in I.D.). I would like to put in a large capacity pump in the pocket but they seem to all have outputs at the bottom of the pump. This orientation may kink the tubing. Thanks

[wayne.b]

Originally Posted by Albicelesail

Well, I have a 20 ft run from the thru hull to the collection point in the bilge. There is approximately a 3ft head. The bilge collection pocket measures 7 in× 7in. x 9in high ( to the floor boards). The maximum bend radius of the tubing is 3 in ( 1 1/8 in I.D.). I would like to put in a large capacity pump in the pocket but they seem to all have outputs at the bottom of the pump. This orientation may kink the tubing. Thanks

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I'd be inclined to recommend a diaphragm type pump which could be located out of the bilge. Here's an example:

Jabsco 36600 Belt Driven Diaphragm Bilge Pump - 12V - 36600-0000 | Anchor Express

[sailnow2011]

Originally Posted by wayne.b

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I'd be inclined to recommend a diaphragm type pump which could be located out of the bilge. Here's an example:

Jabsco 36600 Belt Driven Diaphragm Bilge Pump - 12V - 36600-0000 | Anchor Express

+1 bulletproof.

I like this one as well, so far so good for us. https://www.amazon.com/Johnson-Pumps.../dp/B0073JO0DY

[Sailmonkey]

+2

Use the diaphram pump to maintain the bilge sump, in a higher and always dry unless there's a problem location put one or two of the monster centrifugal pumps.

[Lepke]

The Whale pumps are low profile and the outlet and body rotate.

[Privilege]

Another problem that you will have with a 20' run in a 7" bilge is that once the pump stops running you probably have sufficient water running back down inside the tubing to fill the bilge enough to kick off the pump again...a never ending cycle which will drain your batteries very quickly. One-way valves never work 100% and should be avoided anyway. The only way you can make this work with a bilge pump is to have the 3' head straight up from the pump and the next 20' flowing downhill.


As stated above, the diaphragm gulper pumps will solve the issue but they will never pump as much water as a centrifugal pump and are not suitable for emergency pumping.

[wayne.b]

Originally Posted by Privilege

Another problem that you will have with a 20' run in a 7" bilge is that once the pump stops running you probably have sufficient water running back down inside the tubing to fill the bilge enough to kick off the pump again...a never ending cycle which will drain your batteries very quickly. One-way valves never work 100% and should be avoided anyway. The only way you can make this work is to have the 3' head straight up from the pump and the next 20' flowing downhill.

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I agree that check valves should be avoided whenever possible but it may be the best answer in this case. One of my bilge pumps has one and it has never been an issue in the 13 years I've owned the boat.

[HopCar]

Take a look at the Rule Low Pro series of pump.
They are patterned after the Whale Low Profile pumps but have a choice of two automatic features and they come with a joker style check valve to deal with back flow.
They're rated at a pretty good 900 gph.
Rule LoPro Bilge Pump

[Squanderbucks]

How about putting a bilge pump exit hole in either the side on stern closer to your pump. I realize that a boat heeled over would not want to take in water through the side of the boat but a "flapper" on it's exterior might suffice or use a scupper drain fitting where the ball would seal it from incoming water - or a clam shell. On the stern that may not be an issue.
Diaphram type pumps are usually of smaller GPH and good for keeping bilges dry but not for emergency pumping where a greater volume is desired.
Diaphram pumps also can run dry so if they are on timers and run longer than is needed to pump the water out there is usually no harm. Pickup hoses mounted just right can also pickup that last little bit that standard Rule type pumps leave behind.
I have both. Large capacity Rule on a Water Witch electric solid state switch and a diaphram pump on a 12v programmable timer that comes one twice a day for 2 minutes to get out the last bit of water that the others leave behind in the V of the molded keel. Most days there is nothing to pump put. I have a Bilge Pump Counter on the Main Bilge Pump and it rarely increments unless we have a lot of rain and some gets through the aft deck hatches.

Bilge pump counter is a nice touch as it lets you know if something is out of the ordinary - leaking struffing box or engine coolong pump, etc.