Jim Woodward wrote:

.... in my defense I will point out that the Air Con pump is
almost certainly centrifugal (and, hence, non-PD) while the washdown
could be either, so my suggestion is OK.

Righto



Of course, in your praise of non-PD pumps, you don't mention that they
are unholy nuisances, prone to lose their prime at the slightest
provocation --

The times I've had this problem, it was tracable to a problem(s) with the system.
It's not inherently the nature of centrifugal pumps. However a lot of pumps suffer
from excessive casing clearance either due to wear or cheap manufacture; bad
suction piping runs or sharing a suction with another system & thus having to fight
for prime or being installed above the waterline or having air leaks in the suction
(choose one or all the above).

Having just repiped & remounted two pumps on our boat, and seen a lot of crummy
installations on OPBs lately, it seems like an epidemic. But industry and the
military don't have these problems often (and they pay more, too, hard as that is
to believe).


Jim Woodward wrote:

This is in response to an e-mail from Julian. The return address on

Julian:

If you go to our web site, you'll find a piping diagram:
http://www.mvfintry.com/pix/piping800.png
and lines drawing:
http://www.mvfintry.com/pix/flines800.png

Thanks very much for your second post & links. I am considering installing sea
chests on our boat and this is very thought-provoking, useful material.

Fresh Breezes- Doug King