I'm bidding a job where the engineers have called for 6" 304 s.s. angle legs to be welded to the side of 36" ductile iron pipe. The pipe will be vertical and the legs will "cradle" the sides of the pipe- <0> - like that, but on four points. The pipe will have a hanger above these legs, but there is still going to be a good deal of weight on these welds.We have done lots of custom fittings from carbon steel to ductile but never stainless. Any tips would be great. I dont think we can pre-heat because the pipe is lined with some sort of cement. Thanks.
Welding stainless steel on ductile iron isn't simple, even more considering that the welds will carry "a good deal of weight on them" and preheat isn't possible because of the pipe lining.
Instead of a welded jig to support the pipe, my suggestion is to design a bolted one, in which the s.s. angles would be welded to a pair of suitable clamps around the pipe and bolted to each other. Your company sure has someone who is an expert in pipe supports. With the help of an engineering handbook and a catalog from a pipe supports manufacturer he'll be able to design a good supporting jig.
Plan view Side view
Clamp Bolt Clamp Pipe Clamp Bolt Clamp Clamp Bolt Clamp Clamp Bolt Clamp
Clamp Nut Clamp Pipe Clamp Nut Clamp
Understand the meaning?
A word of warning! As this is a bid, in your quotation you should state that instead of the support called for in the bid documents, you have considered it convenient to offer a different type, which is better for such and such reasons. In this manner, you could have a point over your competitors.
Giovanni S. Crisi
Sao Paulo - Brazil
My plan was to butter the stainless with 309 and then ni-55 . This pipe will be hung from hangers above and stop 3' from the floor. The les will be welded to a 8'X8' x 1/2" 304 sheet on the floor. It is a flanged pipe system, with hangers . Think of this leg set up as more of a locator than as a stand. The engineering team on this site has come up with alot of things that dont make sense. The GC already tried to change it to a clamp type and was told no. I have a good deal of freedom with this GC and I would have gone that route and maybe some sort of ring "shelf" to take the load. But since it has become an issue I dont want to ruffle any feathers here. This is a federal money job, lots of egos you dont want to bruise if you dont have to.
Eric what is this pipe to be used for?
Because depending on the use I don't know that I would go near this......Due to manf. rating and warranty. And also if this is a water type awwa code specifically states that you cannot not weld on ductile iron other then cad welded cathodics.
As far as the pre-heat your fine to about 200deg we commonly pre-heat alot of mortar lined steel lines and pre-heat for shrink sleeves on DIP. I would prolly not want to go above 300 though
This pipe is a fill tube for a huge run-off water storge tank. It is open ended on top and bottom. the legs weld to a splash plate on the floor of the tank. As far as welding on ductile goes, we weld the keeper rings on the spigot end of cut pipe alot. Most of the time it is American pipe (brand) for sewer and clean water.
Ah...You'd prolly be okay since it's not a pressure type system.....but that is alot of weight.....about 6,200lbs?
and why are the using dip? I'm guessing because of cathodic protection?
If this is the case why not go to a epoxy coated 36" steel the cost will be less. and if the motar lining is a must you can go with an american spiral weld or northwest pipe product.
I dont know why they are using the ductile, but all the pipe (storm water) on this job is ductile. Most of the utility pipe we are around is ductile. Some Price Bros. stuff and some plastic, but mostly ductile.
Hmm that's rather odd...... what area are you in?
I know you metioned using a "ring shelf" possibly to take the load have you thought about the use of a bell restraint to be used to attach your hangers?
Eric
Personally, I would also decline to make this weld. For your own good, be sure to get Engineer approval. Obviously there isn't going to be any procedure qualification! Even with the Ni-Rod/ 309 combination, as suggested by pipehead, (I would use Ni-Rod 99, and not 55) this will not be structurally sound. Clamping would be better.
I agree with the above.....don't make SS-Iron welds part of the structure. Try to convince them to use clips and a bolt up method....it takes away the complications.
Eric,
Let's recognize that, so far, none of the people who answered your question (including me) has been able to give a sound solution to your problem.
So, I'll suggest you the following:
The firm of Grinell, from Providence, RI, was, and still is, a prime designer and manufacturer of pipe supports and hangers. They're still in business and you can find them at www.grinell.com
Get in touch with them BY PHONE (don't waste time in sending e-mails), explain them your problem and ask them to recommend one of their supports.
I'm sure they'll be happy to help you.
Giovanni S. Crisi
We have already asked for a clamp type hanger and the GC was told no. One of the things we have to do on city jobs that use federal money is to watch who's feelings you hurt. If I tell one engineer that another one may have a better grasp on this, I dont get called next time they have some nice stainless pipe or even a bucket to repair. There seems to be a huge gap in the places I have worked and where alot of members here work. If we tell them it wont work, they hire another shop. I have changed my plan as to how we are going to do this. We will roll three 4"x1/2" flatbar rings to the od of the pipe. The rings will be welded to the pipe according to the manufacturers specs and the angles welded to the rings with 309. Then we will re-coat the pipe. I dont think anyone will notice (this is inside of a giant concrete tank) and we dont have to prove anyone wrong. Thanks for the replies.
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