B31.3 or Sec. VIII Div. 1?

[kjf1]

The following is an exerpt from ASME VIII Div. 1 code:

"U-1(c)(2) Based on the Committee's consideration, the following classes of vessels are not included in the scope of this Division...

U-1(f) piping components, such as pipe, flanges, bolting, gaskets, valves, expansion joints, fittings, and the pressure containing parts of other components, such as strainers and devices which serve such purposes as mixing, separating, snubbing, distributing, and metering or controlling flow, provided that pressure containing parts of such components are generally recognized as piping components or accessories."

My interpretation of this is that even if an assembly is above the volume, diameter, and pressure limits of the pressure vessel code, as long as it is fabricated from standard piping components, it can be considered as piping and manufactured by the rules of ASME B31.3 instead of Section VIII Div. 1. Is this correct?

The assembly in question consists of a length of 10" XS pipe with B16.9 caps on either end and some 1" Class 3000 couplings through the wall. It looks like a vessel, but can we call it piping?

 

[prex]

No, to be outside of Div.1 coverage a piping must be (and appear as) a piping, that is its use is to collect, manipulate and transport fluids from one location to another.
If it is a vessel (static or quasi static fluid inside) and looks like a vessel it is very likely a vessel!
Anyway the service is the primary element to be considered for classifying: what kind of service is your thing for? prex

http://www.xcalcs.com

Online tools for structural design

 

[davefitz]

It might be outside of div 1 if it is used for "snubbing" or any of the other defined purposes.

 

[PVRV]

It is worth while to go over ASME Sect. VIII, Div.1 barrier limits.

 

[kjf1]

The primary function of this assembly is to add volume to the piping system of a compressor so that when the system is shut down, it settles to a relatively low pressure without having to vent any gas. A secondary function is to collect a small amount of condensate which can be drained from a drain point in the assembly. The fluid is natural gas.

 

[LSThill]

Hi kfriesen (Mechanical)

Is this compressor an API 618 GAS COMPRESSOR?

Leonard@thill.biz

http://www.thill.biz

 

[prex]

If your accumulator has a volume and geometry so that it may be 'generally recognized as a piping component or accessory' then you could consider it outside the scope of Div.1.
However IMHO this decision should not be based onto the type of components used to fabricate it, but on the fact that the whole vessel is, as a standard practice, supplied and built as part of the piping.
If your vessel is somehow special, or anyway if you want to cover yourself by staying on the safe side, then you should build it according to ASME VIII.

prex

http://www.xcalcs.com

Online tools for structural design

 

[kjf1]

Isthill:

The compressor package is built to API 11P.

prex:

Who decides what volume and geometry may be 'generally recognized as a piping component or accessory'?

 

[prex]

Well, who has the last word depends on the local regulations: the engineer that has in charge the design of the system should be the first to analyze the matter and take a position (and correspondingly a responsibility) on that.

prex

http://www.xcalcs.com

Online tools for structural design

 

[deanc]

prex is correct,suggest you check with the Juridiction where it is going to be installed.

Remember to meet U-1c2e the manufacturer needs to call it pipe or a component.
You need to dicuss this with your AIA.