On Tue, 27 Jan 2009 21:12:27 -0800 (PST), engineman
wrote:

I'm trying to improve the performance of the water pump in my steam
powered cycle.
It consists opf a 7/16" aluminum piston witrh 2 O rings at the end
operating in a bronze cylinder.
I'm using a clearence of .001" between the piston and cylinder.
The dimension of the rings is 7/16 od X 5/16 id X 1/16 thick.
I've been having leakage problems and have tried O ring grooves that
had a square cross section a d half round.
I'm looking for info on the best shape and tolerance for the grooves.
I can't seem to find anything in Machinery's handbook.
Engineman

http://engineman69.home.comcast.net/...atewheels.html

The Parker o-ring handbook is available as a 9 MB download.
http://www.parker.com/literature/ORD...g_Handbook.pdf

There's a certain amount of compression necessary to get an effective
seal with an o-ring. The necessary data is pretty well covered in the
book, as well as gland dimensions for static and dynamic seals,
chemical compatibility, etc.

Pete Keillor