Food Grade Stainless questions

By ssbn727 (*****)

Date 03-12-2004 07:59

Hi Brainfarth!
Four words: Orbital pipe/tube welding! You can control your welding parameters to the degree where you can virtually eliminate the need to do any internal grinding for all of the joints. Especially if you choose the correct joint geometry/configuration.

Planning the job is also an important factor!
You probably can lease the equipment and get the training or even the qualified personnel in no time to finish the job in at least half the time it would take for you or anyone else to complete it manually. After all, is'nt time your biggest enemy once you start a job? AMI, Magnetech make some pretty decent equipment for the field so, you might want to investigate further as to what is available in your area or in New Mexico. I know for a fact that it'll definitely be worth your while in the long run to automate the welding process application whichever way you decide and speaking of that - how many joints do you figure on welding all together? If it's at least 50 or more then, this is the way to go. Btw, what will be the longest size of each pipe/tube? Are there any offsets, elbows, sockets, etc?

What may in the beginning take a bit longer to set up, will in a very short amount of time not only make up for the lost time & increased initial start up costs but, also will enable you to complete the job in record time and with virtually no rework or grinding.The result will be a savings in the overall job costs and the time involved to complete the job.

Did you write three lines of 3" Stainless (tube) pipe? Is it a straight run? Do you mean a total overall length of 3300 feet for the job? What part of New Mexico is the job at? As far as certification goes, you might want to check with New Mexico's department of agriculture for answers to just about any of standards that you will be required to meet. There are some other folks here that can give you help with your problem also so keep checking back to read the responses and suggestions because you came to the right place!
Anywho, It may be your best bet for this job! Good luck and let me know what you think!

Respectfully,
SSBN727 Run Silent... Run Deep!!!

By CHGuilford (****)

Date 03-12-2004 17:22

Does it have to be welded? I was thinking of connection fittings that have a gasket to seal between 2 pipes. Sort of like an O-ring in between the ends, not like the victaulic fittings where the O-ring goes over the pipe OD. No voids to grow bacteria in. I don't remember where I saw these before, maybe it was Swagelok?
I have an idea that the price might be right up there with orbital welders but you might want to check out that possibility also, in case it is cost effective.

Chet Guilford

By COLBYNEIBERT Date 03-13-2004 05:35

My family was in the dairy buisness for years,one thing you should check is to make sure you can weld the whole line.The reason being is when the inspector comes through to make sure the facility is cleaned good enough he will want to look inside the pipe atleast they always did when they came by for us,what they used for the line at our facitlity was a form of clamp coupling.The process i would use is heli-arc and to be to code you would have to fuse the root and use a compatible filler for the cap that is the only way you should do anything that is food grade and of course a purge for the back side,you could also mig it if so desired.Just make sure your butt joint is perfectly fitted and you should have no problem depending on the schedual of pipe id use a 0.45 wire for heli-arc or a 0.23 wire for mig.Best of luck to ya

By Brainfarth (*)

Date 03-13-2004 19:00

As far as I know they are 3 seperate 1100' lines. They will be insulated with a heating system laying agains the 3" pipe. As for the length of the pipes and fittings, I have not seen any prints yet so I don't know yet.
On another note, I have been posting on the net for some time on different boards revolving around welding and related topics and I have to admit that for all the posts I have done on this subject, the responces that I have recived from here have been the most enlightening. And I thank you.
Now that's out of the way.. I'm going to find out more information on the subject sometime this week and I'm going to contact NM's department of agriculture about what options I have and if certs are needed.
-Brainfarth
http://www.brainfarth.com/bone.html

By ssbn727 (*****)

Date 03-14-2004 02:21

Hi Brainfarth!
The AWS has a specification for welding of Austenitic Stainless steel tube and pipe systems in sanitary (hygienic) applications.
D18.1:1999 - This document outlines welding standards for use in the manufacture and construction of dairy and food product processing plants. The committee was formed in response to the request of the 3-A Sanitary standards committee, which develops sanitary design standards for dairy and food processing, packaging, and handling equipment and systems. 10 pages, 2 figures. ANSI approved.

They also have a guide to weld discoloration levels on the inside (root) of austenitic stainless steel tube. (AWS D18.2) This is a laminated sheet with color illustration showing the degrees of coloration on the inside of an austenitic stainless steel tube with increasing amounts of oxygen in the backing (purge) shielding gas. Suitable as a specifying tool and a visual inspection guide. Also ANSI approved.Both of these were published in 1999. You can order these through IHS (information handling systems) Global from their website at: http://www.global.ihs.com

Btw Chet, Swagelok does make both orbital welding systems and those "Kwik Clamp" fittings you mentioned. Thanks for reminding me about them!
Their website covering food and dairy products is:
http://www.swagelok.com/industry/fbd/products.asp
These folks got quite a good site as far as tubing, fittings, and welding equipment to help you comply to 3A sanitary standards and accepted practices. They also have some very good application articles with respect to orbital welding applications in the bioprocessing industries.
in this site, they were alluding to ASME section IX certification for welding BPE (Biological Processing Equipment) but, I'm not 110% sure that this applies to Brainfarth's situation. At this point I'm only 100% sure and for me, that's not good enough so,I would definitely contact them to get some clarification pertaining to certification. I would also strongly suggest to fully navigate all of the links and read all of the .pdf's associated with the food processing products they have available. Brainfarth, it looks like you've got some reading to do here so, I would suggest to you that you check out this site's articles, demo's, training brochures, and any other pdf's that will enlighten you further as to what requirements you need to meet in order to tell your friend whether or not you're up to speed on all of the issues, standards, and certifications necessary to complete the job in a timely and cost effective manner.

You can also visit 3-A Sanitary standards Inc. to get the latest standards and accepted practices regarding Milk and Dairy products, equipment and systems at:
http://www.3-a.org/standards/standards.htm
When you get to this site, read about this committee because you'll notice who's involved & their affiliations (these websites are found in the links) and their credentials in developing these sanitary standards. after you're finished reading, you'll want to click the link that reads:
"Click here to view the current list of 3A Standards and purchasing information". now you'll be in Techstreet's website which will give you all of the current 3A standards and accepted practices.
I briefly navigated the lists and found a few that might help, these were listed by their catalog numbers: 3A 605-04 (accepted practice for permanently installed product and solution pipelines and cleaning systems used in milk and milk product processing plants) but this one may be more suitable for your application:
3A 606-05 (accepted practices for the design, fabrication, and installation of and milk handling equipment).
You also may want to take a look at: 3A 63-03 (sanitary fittings for milk and milk products) and 3A 33-01 (polished metal for milk and milk products).

Well that's it for now so, I hope this enlightens you further in your quest to be prepared and to "cover all of the bases" so to speak, in that you can achieve a timely and cost effective completion to this project.

Respectfully,
SSBN727 Run Silent... Run Deep!!!

By Shane Feder (****)

Date 03-17-2004 03:22

Hello Brainfarth,
I am a Kiwi residing in Australia and years ago I spent a great deal of time working in the largest dairy factory in the Southern hemisphere in Taranaki in New Zealand. I first worked as a tube welder and then later as a CWI.
Any piping used for transporting dairy products has to be of the highest standard for hygiene but the process is not really a great deal different to normal stainless pipe welding.
We were welding 316 tube with a WT of 1.6mm with a backpurge of argon or nitrogen.The joint was a square butt with the secret being a perfect fit-up with no root gap at all ( to get perfectly square ends we used a GF saw ).We used a single run with a minimum of filler wire "dabbed" in the molten pool as you "skipped" your way up the weld.
We had a company that tried to use orbitals that they had purchased from an offshore oil company but you could manually weld a 3" butt and be walking to your next weld before the orbital was set up. (It might work if you are pre-spooling in a workshop)
Once you have all your variables sorted out it is pretty easy to maintain a high standard of welding as the WT and fit-up remain exactly the same for all welds.
To remove pipes for cleaning or removing air actuated valves we welded a male/female threaded union to the ends of the pipes.
Purging was achieved using rice paper dams (Water soluble) for large areas or pull through rubber dams that allow you to purge an area only 6" either side of the weld and not the whole pipe.
Purge monitors are a must as any contamination from oxygen will make it impossible to guarantee a weld that will not trap bacteria.
If I can be of any more assistance please do not hesitate to contact me either thru the forum or by my e-mail,
Regards,
Shane Feder

By ssbn727 (*****)

Date 03-18-2004 05:52

Hi Shane!
That company you mentioned tried to weld with an orbital system they purchased from an offshore oil company? It's no wonder they could'nt weld the tubes faster than if one welded manually!!! Wrong equipment for the wrong project application!!!

Check out the equipment at Swagelok... On my previous post, there's a website listed. You might re-think your opinion about using orbital GTAW systems specifically designed for this application after visiting the site.

Do they (in New Zealand) use the same current 3A sanitary standards and accepted practices or AWS D18.1:1999 which was written based on a request from the 3A sanitary standards committee used here in the US at the present time?

Respectfully,
SSBN727 Run Silent... Run Deep!!!