I have a couple of those that I use for other things than on the boat. Like
pulling down a large bag with the Shop Vac before turning on the vacuum
pumps. They are excellent sealing and easy to operate but I still want to
know the answer to Terry's questions about their use in water ballast
systems. When do you open them? Do they need mechanical pumps? And what
happens when you get caught on a tack with the water on the wrong side?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Stephen Baker" wrote in message
...
Valve is a better word.

http://www.valterra.com/Ind/Gate.htm

Used on water-ballasted Open Class boats for years.

Steve
Stephen C. Baker - Yacht Designer
http://members.aol.com/SailDesign/pr...cbweb/home.htm