I have something that I would like fabricated. It's a food-grade stainless steel container that will need to withstand about 100psi, for what that's worth, plus various valves and whatnot. What's the best way to go about finding someone who will take my somewhat nebulous idea and help me fabricate such a thing?
I used to work for an outfit that fabricated SS for all sorts of things. They had Trumpf CNC machinery. The laser alone was $700,000. CNC benders, punches, it was awesome. The stuff would come from CNC so precise we could do corner fusion welds on 16ga. They did take on little projects as a matter of conscience. The owner started out as a oilfield welder, then hit it big with custom fabrication. I guess he didn't forget his roots.
How big is this thing? Can you possibly buy a piece of used equipment and have it modified?
Are you perhaps an inventor? Why don't you know more precisely what you want to make? Fabrication is one thing, but you are asking for design mentoring, design services, handholding, and also fabrication. Most fabricators I know would pass on such a request simply because of the way you are phrasing it. You need a fabricator if you can fully specify the part you want, including a blueprint. Else you need - something else.
When I did sales engineering for a high volume tubing fabricator, I took a series of calls from inventors with similar requests. I'd wish them well and send them on their way. If you didn't need a thousand units, have an accurate print, and have a suitable checkbook, I just couldn't deal with them.
One thing that I noticed immediately was the "100psi container". This tends to be non trivial if the container has any reasonable size to it.
How large a volume will it contain? Above a certain size you may be subject to the ASME code for pressure vessels. If that's the case you might need a bit deeper pockets than you are expecting. The various valves and "whatnots" can complicate the design too. Make sure you plan for all of them up front - adding one or more after fabrication might well require a re-certification.
I know what I want it to do, but I don't know things like how thick the materials would need to be to hold 100psi, and so forth. That's where I'd need the help, so you're right, I'd need more than just the fabrication.
Yeah, that's where I'm concerned. Originally, I thought of playing with a household pressure cooker, but the problem is that I need that valve on the bottom for letting things out properly. I suppose I could modify a pressure cooker, but it would need to be a big one.
I suppose I'm probably over-engineering, too. It probably only really needs to hold 30-50psi, but I'm being conservative, I guess. It would really need a failsafe, too, now that I think about it...
Have you ever seen those huge soup pots in hotel kitchens. They will hold about 50 gallons. Mounted on a stand with a huge handle to tip the pot and pour? I would like to see where and how they are fabricated. And how much one costs. They have the heating elements inside the walls of the pot. All food grade SS.
BTW, what is the difference in number between food grade SS and dairy grade. IIRC, dairy is 304. (??)
They'll be able to either supply your vessel complete or the components you'd need to have someone fabricate it. The toriconical heads are pretty close to what you've shown above. As a point of reference, I purchased two made to order SS heads about 2 years ago; 12" dia, 12ga T304, 180 grit polish, with several water jetted cutouts; $400 for the pair.
Don't ignore the warnings of others re the danger inherent in pressure vessels.
I'm no expert on pressure vessel design but would think that something completely made of indstry-standard pipe rated for the appropriate pressure would be OK. You should verify that with someone that is qualified if you are interested in pursuing it. It might be tricky to get all of the ports you want by using standard fittings.
A phone call to a company that specialises in fabricating small-scale equipment for R&D labs might be in order. If you are near the Chicago area, I might be able to suggest a couple of names.
Oops - NSF is probably some sort of food/sanitation standard or industrial body, right? That's even further outside my area of expertise, but I'd
*guess* that those standards would be related at least in part to material and method of fabrication. Tri-Clover makes off-the-shelf sanitary pipe/tubing with a variety of fittings but I suspect that they don't go nearly as large as you'd need in OD/ID for a 5-gal container unless you can stand a very long vessel.