What kind of welder (person) do I need?

By 4130 Date 05-04-2021 15:32

Since I don't have the welding skills I need to make my next project happen I've come here to figure out how to find a welder with the skills I'm looking for. I've got a project coming up where I need to source and modify a pressure vessel about the shape of a LP holding tank, 8-10 ft long and 40-50 in diameter. I need to take one rounded end off and replace it with a flat steel plate. It needs to have various openings added to include ports for pressure gauges as well as inlet and outlet valves. The vessel needs to hold 45 lbs working pressure and withstand a structural integrity test of about twice that.

Although I don't personally know any welders who can do this kind of work, thankfully I have enough connections I could probably locate one with a little direction. Since getting this made could end up costing $$ I'd like to find someone who does this kind of welding professionally but is open to a side job. My best guess is that boilermakers or pipe fitters would be the kind of welder who could help me out.

Could anyone suggest how I can find a welder with these kinds of fabrication skills?

By Lawrence (*****)

Date 05-04-2021 16:11

Hi Chrome Moly

A conservative point of view here, recommending you go to a shop with code endorsements to do the work with a solid vetting of the plans prior to that by an engineer adept in this kind of work.

Sharp transitions make engineering review and planning a must in my opinion.

By TimGary (****)

Date 05-05-2021 11:12

Maybe you already know, but like Lawrence said, before you do this work you'll need a full ASME certification, as well as the right package of stamped engineered drawings and qualified repair / welding procedures.

By 803056

Date 05-05-2021 16:03

This reminds me of an inquiry I received several years ago. A university professor wanted to fabricate a pressure vessel in the shape of a cube (flat sides, top and bottom) measuring 1 meter per side, pressurized to 20,000 psi (no, the comma is not misplaced), but he didn't want to be bothered by the formalities of ASME. It gets more interesting; he wanted to add viewing ports to each of the four sides.

I told him that I wouldn't touch that with a ten foot pole.

Al

By 4130 Date 05-05-2021 21:52

Thanks for the advice everyone. The good news is I found a design that's not as crude as just welding a flat plate onto the end like I was describing earlier. Apparently that design is used for lower pressure vessels. Although the new design gets rid of the sharp transitions I still want to have the plans run through certification like you guys advice.

That's sure odd about the professor guy though. Usually they're much more order oriented than that.

I've had no experience with almost any of the commercial welding industry at all. What kind of company would I contact to start working on something like this?

By TimGary (****)

Date 05-06-2021 11:16

You need to find a shop with an existing ASME Certification -
https://www.tws.edu/blog/skilled-trades/what-is-asme-certification/