Join Date: Jul 2001
Thanked 28 Times in 27 Posts
Rep Power: 15
Re: anti siphon valve universal m25
The flapper on the forespar marelon loop you go on to describe IS a check valve. Allows air in to when the engine is stopped but closes to prevent water exiting when running.
Jim, you're right in that it is an AIR check valve. Most people reading your post, me included, most likely thought you meant a check valve in the WATER line, which we agree does not and should not exist.
Stu Jackson, Catalina 34, 1986, M25 engine, Rocna 10 (22#)