Jurisdiction / applicability issue between asme b31.1 and asme b31.8 in a power plant 1

[Vitalis 1977]

Dear members,
I would really appreciate your replies on the following issue.
In a natural gas turbine driven power plant design, gas buffering is required. This is achieved through pipe type holders.
Client did not clearly specified applicable design code for piping (see contract specification clause below)

Quote
“all the gas pipes shall be designed, constructed and tested in accordance with BS or ANSI B31.1 or ANSI B31.8 “Gas Transmission and Distribution Piping System"
End of quote

ASME B31.1 does not mention the utiliazation of pipe type holders for gas storage but ASME B31.8, does (not for sour service).
Should I proceed with ASME B31.8 or its scope is not applicable due to the code requirement below?

Quote

"......this code (i.e. ASME B31.8) does not apply to piping beyond the outlet of Customer’s meter set assembly... ”
End of quote

Also as per ASME B31.8, Appendix Q – Scope diagram , Figure 3, code states not to use ASME B31.8 after metering station. Is this our case?

I would really appeciate your replies on this code interpertation issue in order to proceed with my wall thickness calculations accordingly.
Thank you advance...

 

[weldstan]

In all of the gas turbine power plants (well over 50) including HRSG additions that we constructed over a 20 years span, the B31.8 piping ended at the meter station and all gas piping thereafter was built to B31.1.

Pipe fabricated storage vessels were designed and built to ASME VIII, Div.1. Only one or two projects required gas storage vessels.

 

[Vitalis 1977]

Weldstan,
Thank you for the reply.
Three additional queries :
1) There is no ASME B31.1 reference on the utilization of pipe type holders for gas storage in a power plant. Is it acceptable to proceed with this code anyway?
2) Where is the location of Customer’s meter set assembly in a gas turbine power plant?
3) As mentioned above, you designed pipe type holders according to ASME VIII Div.1 for gas storage inside power plant. Pipe type holders are considered pressure vessels? Did you support this design selection from ASME B31.1 code refererence or it was indicted in applicable project's specification? If ASME VIII Div.1 was not specified, its utilization as design basis of pipe type holders was acceptable from end client?

ASME B31.1 listed materials exclude API 5l X.. materials, so calculated wall thicknesses using other available pipe materials are quite big. ASME B31.8 & ASME VIII Div.1 do not provide limitations in the utilization of API 5l X.. materials, leading to significantly lower wall thicknesses.
That is the reason why I'm trying to avoid ASME B31.1.
Of course, if it cannot be avoided, I will proceed accordingly.

Thank you in advance.

 

[weldstan]

Unfortunately that's all I c.an tell you

 

[1503-44]

Weldstan is absolutely correct. 31.8 coverage, as evident by reading its very title and the scope and accompanying diagram in the first section of B31.8, cannot be applied to any piping that is not a part of a gas transportation or distribution network. Coverage of B31.8 stops at the first flange or other type of connection to any donwnstream piping immediately following the sales meter.

ASME BPV will apply to your pressure vessels.

Carefully reread B31.1 for possible allowed use of non-listed, alternative materials supplied under similar specifications.

 

[Vitalis 1977]

Thank you, Weldstan ans ax1e for your replies.
I will proceed accordingly.