Code Jurisdictions

Date 05-24-2013 05:39

This request for clarification stems from an approved drawing submitted on another post as an example of code jurisdictions.
The drawing showed an ASME VIII Div 1 pressure vessel with a welded 4” (100nb) outlet pipe coming directly off the vessel with seven (7) groove welds and the eighth (8th) was nominated on the drawing as the boundary between ASME VIII Div 1 and BEP (Boiler External Piping).
If the piping is classed as BEP then it is obvious the outlet piping has been fabricated in accordance with B31.1
I thought it was totally wrong and did a bit of research and unfortunately it left me even more confused.

1 How can you have Boiler External Piping without a boiler ?

2 If it is classified as Power Piping but the steam doesn’t come from a Boiler does it actually fall under the auspices of B31.1 ?

3 ASME VIII Div 1 allows the construction of pressure vessels that generate steam (eg. U-1(g) -1, 2 & 3) – what would then be the applicable piping code for the transportation of this steam ?

What seems apparent from ASME VIII, B31.1 and B31.3 is that code jurisdiction ends or begins at the first circumferential welded joint.
Herein lies my confusion – which code is applicable for that particular welded joint ?.

ASME VIII Div 1 Clause U-1(e)
U-1(e) In relation to the geometry of pressure containing
parts, the scope of this Division shall include
the following:
(a) the welding end connection for the first
circumferential joint for welded connections [see UW-
13(g)];

ASME B31.1 Clause 100.1.2
Boiler external piping shall be considered as that piping
which begins where the boiler proper terminates at
(A) the first circumferential joint for welding end
connections;
The terminal points themselves are considered part
of the boiler external piping.

ASME B31.3 Clause 300.1.3
300.1.3 Exclusions. This Code excludes the
following:
(d) pressure vessels, heat exchangers, pumps, compressors,
and other fluid handling or processing equipment,
including internal piping and connections for
external piping

Looking at those three excerpts above my interpretation is thus:
ASME 1 Boiler to B31.1 BEP – first circumferential joint falls under B31.1
ASME VIII Div 1 Pressure Vessel to B31.3 – first circumferential joint does not fall under B31.3
ASME VIII Div 1 Pressure Vessel to B31.1 piping – first circumferential joint falls under ?

Your thoughts greatly appreciated,
Regards,
Shane

By Jovi Zhu (**)

Date 05-24-2013 09:01

Shane,

With the same curiosity and confusion I input the key words "Section VIII" and clicked the "search" button on the my PDF Section I. Then in the PREAMBLE I found the following:

Unfired pressure vessels in which steam is generated shall be classed as unfired steam boilers with the following exceptions:
(a) vessels known as evaporators or heat exchangers
(b) vessels in which steam is generated by the use of heat resulting from operation of a processing system containing a number of pressure vessels such as used in the manufacture of chemical and petroleum products
Unfired steam boilers shall be constructed under the provisions of Section I or Section VIII.

I'm not sure if I have found the clue but it seems to me that there is some "superposition" area between Section I and VIII. Maybe there is the possibility that an U-stamped "unfired steam boiler" to be joined to some BEP in the field.

I think it is the designer's responsibility to select the Code section governing the vessel. I'm not working in the design area and I'm just paid to "do as told" :wink:

.

Correct me if any worng understanding~

Cheers,

Jovi

By js55

Date 05-24-2013 16:32

I have not seen the drawing but to me the only way any portion of the pipe could be BEP (ligitimately) is if it tied into the boiler at the other end.
If it a Section VIII vessel without this proviso there is no BEP. However, the designer can impose BEP if the PV ties into the B31.3 designed pipe and woul just like to have the AI involved. I've seen this.
It is not prohibited to turn B31.1 into BEP. BEP is essentially B31.1 with the AI and Data Reports.

By Shane Feder (****)

Date 05-29-2013 13:01

Jeff,
This was posted by Joey on the "ASME Tank" posting and I thought it was totally wrong

http://www.aws.org/mwf/attachments//13/246813/PVDrawing.pdf

Cheers,
Shane

By js55

Date 05-29-2013 19:51

Shane,
I would not have run the Section VIII scope so far out but I am not sure what they are doing is prohibited. This question is best left to a design guy. I have never seen anything like this.

By Shane Feder (****)

Date 06-15-2013 00:07

"Shane,
I want to throw out some food for thought. I have been told by A.I's in the past that U-1 (e) (1) (a) means the connection prep. Not the actual weld. "the welding end connection" for the first circumferential joint for welded connections...... also if a slip-on or socket weld connection is used, they are not considered part of the boundry. What are your thoughts on that? "

Jim

Jim,
I have been told the same thing and it makes a little more sense to me now. :confused:

However, it still remains a little unclear to me (from a code perspective) who has jurisdiction of the first weld off a pressure vessel.
If all welds on a pressure vessel must comply with ASME VIII and all welds on a piping system must comply with B31.1 or B31.3 - who "owns" the tie-in weld between the two.
B31.1 is quite clear that the "termination point" which is the first weld falls within the scope of B31.1 but that is applicable to Boiler External Piping.
B31.3 is quite clear connections for external piping from pressure vessels do not fall within the scope of B31.3.
ASME VIII has the welding end connection (but not the actual weld) within its scope.

Obviously there is no difference in how it is welded - with an ASME IX WPS and ASME IX qualified welder but what about acceptance criteria ? What if all three codes have different acceptance criteria ?

Cheers,
Shane

By Jim Hughes (***)

Date 06-15-2013 11:40

Thanks Shane.
I spoke with our A.I about this just recently because we had some Div. 1 vessels come to a project in KY that had a 2.5 Inch pipe coming out of it with no flange connection. He interpreted U-1 (e) (1) (a) as the prep and said that B31.3 had jurisdiction at the weld (to be clear the piping connecting to vessel was designed to B31.3) and that it was not part of the Div. 1 boundary.

I agree with js55 in that the designer can change the boundary to exceed ASME Sec VIII, and sometimes might have good reason, such as contract requirements, but it does cost more to do so. If that particular drawing would have come across my desk, I would have bleed all over it and asked for justification, just from a cost standpoint.

Thanks
Jim

By Shane Feder (****)

Date 06-15-2013 11:54

Jim,
It is an interesting subject (for me anyway).
How would you (or your AI) interpret the below which seems to exclude B31.3 from the "connection" of external piping to a pressure vessel.

300.1.3 Exclusions. This Code excludes the
following:
(d) pressure vessels, heat exchangers, pumps, compressors,
and other fluid handling or processing equipment,
including internal piping and connections for
external piping

Cheers,
Shane

By Jim Hughes (***)

Date 06-15-2013 15:00

Shane,
by looking at Fig. 300.1.1 and by reading and interpreting "connection for external piping" The operative word here is "for" not of. Now, that is out of B31.3 2010 and maybe it says somethng different in the version you are looking at. That is how I interpret this. I'm not saying I am completely correct and I could be missing something.

Thanks
Jim

By Shane Feder (****)

Date 06-15-2013 15:16

Jim,
I am reading the 2010 edition and I cannot see the difference between "for" or "of".
Connection for external piping....
Connection of external piping ......
IMHO whichever word you use the joint where the B31.3 pipe connects to the pressure vessel is not within the scope of B31.3 - I may be the one who is totally misinterpreting this and that is why I posted the question,
Cheers,
Shane

By CWI555

Date 06-15-2013 17:59

In my opinion, you are reading too much into it.

By Jim Hughes (***)

Date 06-18-2013 17:07 Edited 06-18-2013 20:53

Shane,
thanks for your reply. I am trying to get it right so please bear with my persistance. Look at Fig. 300.1.1. what is your take on its content?

Thanks
Jim

By CWI555

Date 06-15-2013 17:57

Shane,

I am shooting from the hip here as I don't have the code in front of me.

The drawing posted doesn't make any sense. Should not the pressure boundary for the vessel end at the first prep that 'is not' directly contacting the pressure boundary of the vessel?

Regarding this:
"B31.3 is quite clear connections for external piping from pressure vessels do not fall within the scope of B31.3."
What constitutes 'external' piping from VIII pressure vessels? If 'all' piping external to the vessel were included, there would not be a B31.3 code or other process code for VIII. In my experience it means the piping with a direct connection to the pressure vessel is Section VIII, and that piping 'not' directly connected falls to the process code.

As others have noted, the drawing should be bleed over and sent back to design for clarification. I would be very surprised if an AI bought into anything else. (then again, maybe not given the quality of newer AI's these days)

By ozniek

Date 06-20-2013 13:20

Hi Shane

Been "off the ground" for a while, so have not had the time to check this out in any detail till now. I think the main issue here may be some misinterpretation of terms where ASME VIII Div 1 and B31.3 are concerned. From my searches, I do not seem to see any conflicts. My take on the matter is as follows:

1) The "connection" being referred to in ASE VIII Div 1 is not the weld between the vessel and the piping, but it is the part that serves as the connection between the vessel envelope and the adjoining piping / valves / other vessels etc. In other words, the "nozzle" is a specific type of "connection". This can clearly be seen by looking at UW-15 and UW-16. (In particular, UW-16(a)(1) tells us that nozzles, connections, reinforcements, necks, tubes etc are defining the same type of construction and form a category D weld between the nozzle (or other term) and the shell, head etc.)
2) Within the understanding of (1) above, ASME VIII Div 1, U-1(e)(a) is referring to the particular nozzle type construction, not the actual weld.
3) Within the understanding in (1) above, ASME B31.3 is referring to the nozzle type construction of the PV in the exclusions in 300.1.3(d), NOT the actual weld.
4) It is very clear within B31.3 that the first circumferential weld falls within the scope of B31.3. (Para 300.1.1(c) has the last sentence: The joint connecting piping to equipment is within the scope of B31.3. Also, Fig 300.1.1 again shows this clearly, and has a "general note" at the bottom: The means by which piping is attached to equipment is within the scope of the applicable piping code.)

Using this argument, I believe that the B31.1 interface also becomes clear, so I will not take the trouble of delving into the power codes.

Hope that makes sense.

Regards
Niekie

By Shane Feder (****)

Date 06-20-2013 13:29

Thanks Niekie,
I missed the clause 300.1.1(c) which clarifies everything.
Cheers,
Shane

By Jim Hughes (***)

Date 06-24-2013 10:25

Ozniek,
thanks for the reply.
As mentioned earlier in the posts we had come to the same conclusions and had an A.I confirm. One of the other issues was what seemed to be a contradiction between 300.1.3 (exclusions from B31.3) and Fig. 300.1.1 which I believe we have rectified.

Thanks
Jim