B31.3 Fluid Service Determination - Who?

[tr6]

Who determines the fluid service category to be used in the design, fabrication, examination, and testing of the piping for a piece of process equipment?

 

[TBP]

Talk to the local inspection authority. There are many local spins on codes, and it's VERY disappointing to get a lot of pipe hung, then find out that "you can't do that here..."

Or, they may just tell you that it's left up to the designer.

 

[pipewelder1999]

Chapter 1 "Scope and Definitions" indicate that the owner indicates the fluid service category. See para 300 (b) (1).

Have a nice day Gerald Austin
Iuka, Mississippi

http://www.weldinginspectionsvcs.com

 

[tr6]

Thank you Pipewelder.

Now consider this. Mr. Owner orders an equipment package with welded piping from an OEM. The design pressure is under 100 psig and the design temperature is under 100^F. The equipment package handles various pressurized fluids in its process: water, concentrated acid, and caustic. The contract/PO only states that all piping shall be designed, fabricated, examined and tested in accordance with ASME B31.3.

What is the OEM's obligation, responsiblities, and /or liability in meeting the terms of the contract? Specifically, what level of examination does the OEM perform on the welded piping for the obvious "nasty" fluid services?

 

[pipewelder1999]

This is only opinion and I am little experienced in these matters.
If the OEM has supplied said equipment under the advertised conditions in the past with little to no history of problem associated with piping fluid service category and the purchaser/owner didn't specifiy or indicate any service conditions outside of the manufacturers recommended service. The owner got what he paid for if he did not specify design criteria.

I would think the end user of such critical equipment would be knowledgable about the code they are ordering to and understand the requirements for specifying the fluid service category.

Have a nice day Gerald Austin
Iuka, Mississippi

http://www.weldinginspectionsvcs.com

 

[TBP]

pipewelder1999 - I've worked in a great many plants where the owners/managers ordered equipment with no idea whatsoever about what codes were supposed to be met. It's gotten considerably worse over the past decade or so. A huge number of small to medium plants (and some surprisingly large ones) have downsized their engineering and maintenance staffs to the point where there are only electricians and millwrights left (not enough of either, and the line between them gets more blurred all the time), with (usually) an electrical engineer in charge. The amount of non-code compliant pressure piping and systems out there is just staggering. Most of these outfits don't have enough resources or know-how left to even select knowledgeable consultants or contractors - so they drop back to what the accounting department knows best - "low bid". Many plants are run by the accounting department. Not good. Not good at all.

 

[tr6]

TBP, You are right. I have worked many years on the other side, as an OEM. I've seen a lot of specification packages, and it seems that those who have composed a specification feel that as long as they include some reference to a piping spec, whether it is B31.1 or B31.3, that they are covered and the code will take care of them. Not knowing that there is more to it than that.

Hence my orginal question - given the level of competance, or lack of on the end user side, it would seem to me that the OEM has an obligation to point out the code requirements for nasty fluid services. Of course the OEM should get paid for this, and not be made to eat the cost as "Being Required By Code".

 

[TBP]

tr6 - Most of these folks are under the impression that the "designer" (who is, around here, more often than not is an HVAC outfit who imagines they can do pressure piping design), low bid equipment vendor and equally low bid contractor to know and meet the applicable code for pressure piping. I got sick of having my pressure piping information being basically ripped off and handed to millwright or residential plumbing shops, so I'm much more stingy with that kind of info now, until there's a PO in hand.

I don't know of any jurisdiction where anyone other than the plant owner bears total reponsibility for code compliance. Thanks to decades of lacklustre (as in basically none at all) inspection, almost NONE of the plant people are aware of this. And it's not like those that are win any friends among upper management. They're usually seen as an obstruction (i.e. "not a team player&quot to the lowest possible bid for a given project. Go on... ask me how I know that.

 

[reichertc]

I have heard of several situations where an owner tried to pressure a consultant to recommend categorizing a fluid service as "normal piping service" when the consultant felt that it was category M. The engineer ended up advising the owner (off the record) that he felt that the service was Category M, but it was totally the owners responsibility to designate it as such.

Please note that extremely hazardous substances can be designated as normal fluid service if the design is such that the potential for personnel exposure is not judged to be significant. (double containment piping for example.)

 

[TBP]

While the owner typically bears all responsibility as far as code compliance goes, that's not to say that they wouldn't sue everybody in civil court who was on site during that project, from the designer, to the vendors, to the contractors, and guy who drove the coffee truck.

I have no doubt that if there's ever an ugly situation regarding the installation, those same owners who wanted to cut every corner they could find, will set new speed records for calling out the lawyers and going after the "incompetent consultants". Anyone who doesn't take a pass on jobs like that is looking to wind up like Arthur Anderson.

 

[stanier]

I am unsure about US and Canadian institutions as I am Australian based. I am a fellow of the Institution of Engineers Australia and the Institution of Mechanical Engineers. Both the local institution and the UK one require that a professional engineer inform an ignorant client of problems. ie We have an obligation to protect the uninitiated from themselves. Its a great burden for professional engineers but thats life. We chose our profession.

Also the insurer will no doubt see that the knowledgable person as the one responsible if something goes wrong.

In answer to the original query I would make the customer aware of his responsibilities. Direct him tothe local inspectorate or consultant and await an answer. If you want to play hardball let him know that the contract is on hold until he advises yoiu and that you will seek prolongation costs under the contract for any delays or changes. A more prudent action would have been to raise the matter when you tendered. Sharing knowledge is a way to immortality

 

[dixiedean]

What is the maximum allowable pressure for 8" and 14" piping
system of A 106 grade B and grade C.

 

[stanier]

Dixiedean

It depends on the pipe schedule and temperature of operation. It also depends upon the design code used for the process in question.

If you dont know this I suggest you get someone to at least check your calculations. Sharing knowledge is a way to immortality