API 5L pipe not allowed in ASME section 1

[processeng01]

Hi everyone,

Can anybody shed some light on why no API 5L pipe material is allowed in boiler external piping?

Thanks

 

[CodeRef]

see link for further discussion:

http://www.eng-tips.com/viewthread.cfm?qid=30984&page=5

Now, for my two cents... you stated "boiler external piping" or (BEP) and not "non boiler external piping" or (NBEP). BEP requires compliance to ASME Section I, for which API 5L spec is not currently adopted (see Table A-360).
However, the Code allows the following..... Material identified to a specification not permitted by Section I, or material procured to chemical composition requirements and identified to a single production lot as required by a permitted specification may be accepted as satisfying the requirements of a specification permitted by Section I provided the conditions set forth in PG-10.1.1 or PG-10.1.2 are satisfied..........
For the sake of discussion alone, API 5L is not in Table A-360 for the same reason a a coat hanger is not specified as filler metal (unless it is properly qualified and you can show weldability).
A manufacturer would have to take on the responsibility of verifying the laundry list of items listed in PG-10 and throughout the applicable referenced codes and then be required to defend their decision. It is much easier staying within the given boundaries of the ASME Code without making it more complicated.

There are three kinds of people in this world; those who can count and those who can't.

 

[processeng01]

Dear CodeJackal

Thanks for the reply. My question is if there is a specific technical reason as to why API 5L is not allowed in boiler external piping. Is it just a matter of boiler code not recognizing material from another standard, namely API.

Thanks

 

[deanc]

CodeJackal told you....but to put it simply, API 5L has 47 flavors and some are not suitable for steam.

 

[jte]

processeng-

You woudln't take a BMW engine and put it into a Mercedes and expect Mercedes to continue to honor the warranty unless Mercedes had approved the use of the BMW engine in advance. Similarly, ASME has not endorsed the use of API 5L pipe in its scope. It may work well, it may not. If you choose the right flavor of 5L it may work well. But the responsibility lies entirely with you and the project will not pass an ASME based inspection.

jt

 

[unclesyd]

Back before most of you started in this business API 5 piping had a reputation for not being the best quality material. As stated above the proliferation of grades didn't help matters. The greatest number of additions came during the construction of the Alaska Pipe Line. It was said in the chemical industry that if a batch of pipe didn't meet the proper API 5 specifications they created a new grade.
We had trouble getting CS piping during that period and tried to some API grades. The result was that what ever you ordered it was stenciled on the pipe even if they had to paint over the real grade mark of the mill.

 

[stanweld]

API 5L permits welded pipe to be manufactured by a number of processes, among them continuous butt welding. Having been involved in its manufacture and testing, such pipe would never be recommended for Section I applications. Additionally, inspection and testing methodologies would not be acceptable under SA specifications. AS deanc so aptly stated there are too many flavors which would require prohibition.

Note that most manufacturers today tripple and quadruple stamp seamless carbon steel pipe as API 5LB, API 5LX-42, SA-53B and SA-106B.