I'll let somebody who knows more about the valve block answer that but what I do know is Vaseline on rubber O'rings is not a good idea.
Any petroleum based product on rubber will make it harden and crack. AKA. KY jelly instead of Vaseline - lets not go there?
Any petroleum based product on rubber will make it harden and crack. AKA. KY jelly instead of Vaseline - lets not go there?