Bilge Pump 3700 Gallons Per Hour

[Jim@sea]

Just bought a 12 volt £28 bilge pump. It says it will do 3700 gallons per hour. If its true thats very fast.
I could understand it if it said 3700 Liters per hour.
Anyone used one. (bought it to drain a pond but will keep it for my next boat)

 

[Malish]

US gallons might help? to what height??

 

[macd]

I'm often suspicious of numbers like that one. It sounds like they stuck a finger in the air and guessed at one gallon per second then added a bit so it wasn't obvious.

How big is it? Perhaps they did mean litres.

 

[lw395]

That could be the right figure for zero lift and zero length of pipe.
The drag of the water through the pipe will reduce it, as will the back pressure from lifting the water.

 

[pvb]

That could be the right figure for zero lift and zero length of pipe.
The drag of the water through the pipe will reduce it, as will the back pressure from lifting the water.

Yes, that's the way these pumps are rated. By the time it's installed, it'll probably do about 700 gallons an hour.

 

[Martin_J]

I have a couple of Johnson 4000gph electric bulge pumps on board. They cost rather more than £28 though.

4000gph straight and level but they say 2600gph with 1m head.

Have you checked what the current draw is for this new pump? Mine needed to be fused at 25amps which is more than a lot of the standard bilge pump switches will cope with.

 

[ghostlymoron]

You guys must have very leaky boats?

 

[geem]

We have enough automatic bilge pump capacity to pump 19,000 litres per hour. About the same as a 50mm diameter hole 600mm below the waterline. Being a 44ft boat it would take us a while to sink without that much pumping capacity as we would need to get a lot of water in the boat to over come the buoyancy. Obviously a smaller boat would sink quicker for the same size hole 600mm below the waterline so you could argue pumping capacity in a smaller boat is more important as they would sink faster for the same size skin fitting failure. One of our pumps is a Rule 3700gph (3.7 American Gallons per litre)

 

[pvb]

One of our pumps is a Rule 3700gph (3.7 American Gallons per litre)

Think your conversion is suspect! Anyway, you'd be lucky to get a quarter of that output in real world conditions.

 

[geem]

Think your conversion is suspect! Anyway, you'd be lucky to get a quarter of that output in real world conditions.

Opps!! Result of far too much rum punch at the BBQ last night. I meant 3.7 litres per America gallon of course........