Compressor B31.3 or Sec. VIII 1

[eric37]

Hi

We have to change piping between defferent stage (4 stages all above 15 psi) of a air compressor.I want to now if the fabrication and inspection are under B31.3 or sec VIII. The client scope refer to both...

The scope is not clear.

Sorry for my english
Thanks

 

[metengr]

eric37;
Use B31.3.

Why?
See below. which is an excerpt from ASME Section VIII, Div 1

Scope
...U-1(c)(2) Based on the Committee’s consideration,
the following classes of vessels are not included in the
scope of this Division; however, any pressure vessel which
meets all the applicable requirements of this Division may
be stamped with the Code U Symbol:
(a) those within the scope of other Sections;
(b) fired process tubular heaters;
(c) pressure containers which are integral parts or
components of rotating or reciprocating mechanical
devices, such as pumps, compressors, turbines, generators,
engines, and hydraulic or pneumatic cylinders where the
primary design considerations and/or stresses are derived
from the functional requirements of the device;....

 

[rmw]

Depends on what the meaning of "integral" is.

rmw

 

[eric37]

Thanks for you answer

 

[rmw]

So, if I take a stand alone gas turbine compressor, say an axial compressor shaft driven by other parts of the turbine engine train and put an after cooler on it and in line with it, axially, so that the shaft from the driver passes through the aftercooler (shaped like a donut), and connect it to the compressor with ducting or diffusers, is it a part of the engine or is it a stand alone Hx subject to the PV code? The compressor is clearly a piece of rotating equipment easily identifiable by certain features and the Hx is clearly a Hx, tubes, fins, etc, capable of being moved off axis and having the compressor discharge ducted to it but otherwise functioning the same. Nothing about it has the appearance of the other engine parts. Is it part of the engine, or is it a stand alone Hx that happens to coupled in line with a turbine?

This is a serious question made deliberately vague, sorry.

rmw

 

[metengr]

rmw;
I will try to give you my (Code view) interpretation;

Question;

Is it part of the engine, or is it a stand alone Hx that happens to coupled in line with a turbine?

Reply; The Hx is not considered integral with the compressor, therefore it could be under the Scope of ASME Section III, Div 1.

 

[rmw]

Metengr,

That is my take. It is not integral to the compressor, or the next component in the string but it is integral to the overall unit, hence my first post in this thread.

That said, removing it doesn't prevent the engine from running, just makes it run really crappy.

Sorry I am having to be so vague.

rmw

 

[GenB]

this pipe or cyl over 6in id may be stamped U or piping Code.
Jurisdiction acceptance is another thing.
If customers requests Sect VIII U stamp, give it to him or her

 

[pvwander]

This is my take on the subject.

My actual experience for Compressor unit, Manufacturer has applied ASME U stamp for all the auxiliary process equipment integral to the unit like K.O. drum, Inter cooler & Bypass Cooler as part of the overall unit. They are stand alone equipment connected to the Compressor by piping lines not integrally part of Compressor.

I would think also the reason for U-stamping was based on para. U-1 as mentioned above, since these type of vessels are not included in the scope of Division 1.

U-1(c)(2) Based on the Committee's consideration,
the following classes of vessels are not included in the
scope of this Division; however, any pressure vessel which
meets all the applicable requirements of this Division may
be stamped with the Code U Symbol:

.
.
.
(c) pressure containers which are integral parts or
components of rotating or reciprocating mechanical
devices, such as pumps, compressors, turbines, generators,
engines, and hydraulic or pneumatic cylinders where the
primary design considerations and/or stresses are derived
from the functional requirements of the device.

-pvwander