View Full Version : Food grade stainless questions
03-11-2004, 12:25 PM
A buddy of mine has asked me if I could do a job for him in New Mexico. It's to lay down 3 3" x 1100' stainless pipes for a dairy farm. I have fabricated and welded food grade tankers before, but all that was inhouse and easily accessible. Didn't have to worry about material types(shop forman had the aws rules figured out and whatever rule fell into that catagory) or certs(inhouse certification).
So now I need to know a few things..
What is the process to butt 3" pipes together? With tankers we had to do full pen welds and grind any obstructions down flat then polish(I think it was realistically about 200 or 400 grit) the inside area down so bacteria couldn't stick and grow, how do you reach down an 1100' pipe to work the inside?;)
What certs will I need?
Am I overlooking anything?
03-11-2004, 12:31 PM
I don't have a clue of how to do that.
You might want to post that question over on the AWS sight.
03-11-2004, 10:17 PM
My little knowledge of food grade stainless which is 304, is to weld with no filler I believe and have the pipe filled with Argon gas. This is called back purging, the area of penetration in the inside will be shiny or silver colored. I have back gased parts in my shop and the area inside is beautiful.
Well, when the guys did the hundreds of feet of 1.5, 2, 3, and 4 inch dairy tubing, they cut them all square on site with a rotary saw thingy, clamped them onto a stand, and tacked em up. Fill lines with argon, and do a damn good job welding them up. The guys that did our job were high dollar, but top notch. Can't hardly tell where the welds are without looking real close, also hard to feel. Would reccomend them to anyone, They were out of Portales, NM. Where are you going to? The cheese plant in Clovis?
Had some local guys change a little bit later, they half assed it and I was not impressed, turned into super pissed when the bill showed up. Had them re do a piece in their shop and they still could not even come remotely close to the work the other guys did on site.
I will try to dig up some pics later tonight when I get back to my other computer
03-11-2004, 10:43 PM
What process did they use to weld it up on the site? Must have been TIG if you had to look real close. TIG'n stainless isn't too difficult of a thing. I've had to dig up stainless tankers in all positions so I have plenty of experience in that. Do you know what certs you have to hold to weld stainless for the food industy? And I'm wondering if there has to be any insurance or anything like that.
DUH, I kinda neglected the part that became obvious to me, the TIG part.
I'm not sure what certifications are needed, or about insurance.
Where is this job in NM?
03-12-2004, 02:19 AM
I think it more like my slow thought process clicking along while my fingers followed.. But I've been searching all over the net to find out what kind of certs that are needed and I ended up at the AWS site, browsing for hours to find that any information specific enough has to be bought. Check <a href="http://www.aws.org/catalogs/index.html">AWS</a> and you'll see a big list of literature that you can buy. As for NM, I'm not sure.. When I talk to him tommorow, I find out some more details about this project.
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