replying to Danny D., Oliver Street wrote:
You did the right thing. The choices are substantially butyl rubber, nitrile
rubber, BUNA-N, and Viton. The correct choice for an application is driven by
cost vs. the resistance to whatever environmental stress is present that will
either break down the rubber or penetrate and swell the rubber until it's too
soft. Viton is between 1.5x and 2x the price, and has several times the
resistance to oxidation salt and chlorine, and swells about 1/10 to 1/4 as
much as the others in oil and grease, and less in water. The pecking order
would be Viton, Nitrile or BUNA-N, butyl, unstated elastomer.

--
posted from
http://www.homeownershub.com/mainten...to-749807-.htm