"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
All this to avoid a check valve?

Sure, mental exercise keeps you young.

You've had good luck with your check valve but others, including
myself in different applications, have not.

Do you strip your bilge out? With a hose full of water and the pump
and hose up to the check valve full of the trapped air, I don't see
how the pump could start pumping again. As long as you don't let the
water level fall below the check valve, it should be fine.

Of course, I'm now proposing a system with a check valve in it. But,
there is an even easier way. Just put a 1/2" PVC pipe siphon into the
cofferdam. It won't do anything as the water level rises. Once the
cofferdam fills, the siphon will keep the level in it the same as the
bilge and the cofferdam will empty as the bilge water is pumped out.

This is dead simple. Float switches should be protected from surge
and debris anyway.

BTW I actually like Garland's big pump - little pump solution but I'm
now committed by piping and purchase to the dual pump solution. For
other reasons, I want entirely separate and equal loads on each
battery.

Here's what the system would look like. Except for the 15 minutes
work to put in the siphon, it's pretty much what I would build around
the float switches anyway.

http://home.maine.rr.com/rlma/Siphon.jpg

It couldn't be much simpler.

--

Roger Long