On Sat, 13 Nov 2010 08:14:19 -0500, I am Tosk
wrote:

http://www.jamestowndistributors.com/userportal/show_product.do?pid=622&familyName=Buck-Algonquin+Ball+Valves

The arrangement would look something like this:

SeacockstrainerT-fittingraw water pump (one side of T)
reducerball valvepipe
nipple (second side of T, for attachment of flushing hose or
antifreeze)

I don't know about boats, but under my sinks I like a petcock instead of
a flow valve, just in case something knocks into it.. Too easy to open
or close by accident. Have you ever heard of such a problem on a boat?

These things are usually hidden away where there isn't much chance of
hitting them accidently. Of course the other good thing about ball
valves is that it is intuitively obvious what position the valve is in
just by looking at the handle.