I have a 5" bore cylinder from a splitter that I want to change the port size on so I can use a 28gpm pump. It has 1/2 npt ports and the hole drilled through the cylinder is probably closer to 3/8ths. I can weld but I'm certainly no pro. Any reason welding on 3000psi rated weld on pipe outlets should scare me? I feel like the worst that can happen is I have a leak but maybe I'm missing something? I would take the cylinder completely apart first obviously.
I have done that before with no probs but I have been welding for 20 plus yrs if u not comfortable take it to a weld shop but try to do the prep work first so they just weld it on then it won't b so hard on your pocket book.
Take it apart, grind or sand the paint off a inch around the port(there's a ridiculous shop by me that yells at employees for grinding paint before welding) and ask them to tig weld it, any half decent tig welder should make a perfect seal that should hold forever, I'd weld it for you if you were close! Only worry of mine would be oil leftover inside but should just smolder and smoke.
I'm a decent welder and own a tig. I welded a bunch of new bungs in propane tanks that I used for hot water storage for my wood boiler with no leaks the first time. The way I see it, since it is liquid and fairly low flow, worst case scenario is I develop a leak and I shut it down unlike a failure with something like pressurized air that can be catastrophic if there is a failure. I just wanted to make sure I'm not missing anything. Are you saying they don't want employees to remove paint before welding? Tig welding through paint must be a blast.
sounds like you are confident in your abilities and have done this type of stuff before, done right it should not leak. seeing you well have the cylinder apart maybe rig up a argon purge and make multiple pass's around the fittings. and as you already know its all about the prep when it comes to tig welding
Yea Yea my buddy got fired for doing what any welder would and should do, they wanted to get sh!+ out the door no matter how it looked. I prefer quality over quantity. I think your fine just tiging it on, I'd choose tig for that anyways, unless you have capabilities of spray transfer with a wire feed, you could do that, tig it with some 70000 tensile strength filler, a 1/8 bead should hold just fine. Just be sure you dont set it in to far so anything catches on it
Really don't need the purge on mild steel, mild steel doesn't sugar the way stainless does, only time I've ever really back purged was on light gauge and food grade material. Unless your using vegetable oil instead of hydraulic oil You know what your doing I see no worries in welding it on. Just make sure you have clearance inside the bore
it also helps if you have a poor fit up as well as displacing any flammables hell I've been known to run purge on aluminum
Thanks for all the advice everyone. I can't figure out why all of these damm cylinders have such small ports to begin with. A 5" cylinder with a 1/2" port is ridiculous and to make it even worse the hole drilled through the cylinder is tiny-much smaller than the 1/2" npt fitting. My 252 is capable of spray transfer but as I understand it I would have to get different gas than the 75/25 that I have so I'll tig it. I was planning on using the forged steel fitting on the bottom left of this page unless someone has a better suggestion. They are meant to sit on top so no issues with sticking too far in the cylinder: http://www.mcmaster.com/#standard-metal-pipe-outlets/=yj6kxy
That should be fine, yea to do spray transfer you would need 90/10. When I get the extra cash I'll be buying a third bottle for that so I feel more comfortable doing heavy welding for customers.
