Welcome to ModelEngineMaker !If you have problems registering or logging in, please use the contact menu option to request assistance.
Geoff,I stopped using Viton "O" rings after I read the following (https://en.wikipedia.org/wiki/Hydrofluoric_acid ) especially when you scroll down and read " Health and Safety "For the past 15 years I have used only Silicone "O" rings in steam cylinders, infact Suppliers specifically state that Viton "O" rings are for pump rams and glands only.I have a copy of the Silicone "O" ring groove dimensions if you would like a copy P.M. me and I shall mail it to you.George.