I am putting together the parts and fittings for the boiler for my Stuart engine. I read Tel's excellent post on making simple nipples (?olives) for pipe connections - but what material should be used for them? If its copper rod - should it be annealed first to make it "squashy"?
Secondly - in some of the recipies I am following for fittings - reference is made to "O" rings (in cap seals for a lubricator and glands for a simple regulator) - will simple silicone O rings (black automotive type) suffice or should something special be used in view of the temperarures involved?
I apologise for these dumb questions - but I have never piped anything up before and am very confused as to how to do it for best practice. Can anybody kindly help please?
Brass is a more commonly used material for pipe nipples, just use it as it is- no heat treatment/annealing required. Though there is no real reason not to use copper, just a bit more difficult to machine.
Unlike household compresion fittings it is usual to solder the nipples to the pipe so any annealing would be wasted by the soldering process, though allowing to cool naturally rather than quenching will keep the pipe soft.
Nitrile O rings are better as they are less affected by oil & heat.
Agreed, I just use brass for the nipples. Now here's another hint with 'em. When it comes to fitting them to the pipe, bash the end of your stick of silver solder out pretty thin, then snip it to an acute point, that way you will be able to apply just the tiny bit you need and not a big blob.
BTW, the silver soldering process will anneal the pipe regardless of whether you quench it or let it cool slowly. I prefer to quench as it shocks off as lot of the crap.
Decisions, decisions Peter, another way you might want to consider is to use a flared end on the pipe and a cone end on the fitting, like the brake pipes on a car/motorbike. Saves Silver soldering. Regards Ian.
PS. No 1 is OK for delivery WHEN I debutt and sort the mags.