Fastening, Joining & Assembly Blog

Fastening, Joining & Assembly

The Fastening, Joining and Assembly Blog is the place for conversation and discussion about fasteners and hardware, design for assembly, adhesives and sealants, and welding and joining technologies. Here, you'll find everything from application ideas, to news and industry trends, to hot topics and cutting edge innovations.

Previous in Blog: The Robotics Market in China   Next in Blog: Standards Q&A: Interpreting ASME’s Post Weld Heat Treatment Requirements
Close
Close
Close
4 comments

Standards Q&A: ASME’s Changes to Vessel’s Painting Welds

Posted September 11, 2016 12:00 AM by reprendergast
Pathfinder Tags: ASME standards

Have you ever wondered why certain standards have changed? It’s an engineer’s responsibility to research and follow the latest standards, but understanding why they have changed can be helpful when bringing these revisions back to the workplace. This week we take a look at an engineer’s question about a change to ASME Section VIII pressure test rules.

Question: While reviewing Section VIII, Division 1 pressure test rules, I see that painting or coating pressure retaining welds in a vessel prior to the pressure test is now prohibited. When was this change made, and why?

Reply: Several years ago, tests were conducted to assess the pressure containing capability of different paint systems when subjected to a hydrotest. The test results clearly show the ability of paint to mask leak sources in the pressure containment. On the basis of published test results as well as recommendations from organizations that operate and maintain pressure equipment, Section VIII approved revisions to both Division 1 [UG-99(k) (hydrostatic test) and UG-100(e) (pneumatic test) ] and Division 2 [8.1.2(e)] that will require that vessel pressure-retaining welds not be painted or otherwise coated either internally or externally prior to the pressure test unless permitted by the user or his designated agent.

When painting or coating prior to the pressure test is permitted, or when internal linings are to be applied, the pressure retaining weld shall first be leak tested in accordance with ASME Section V, Article 10. This test may be waived with the approval of the user or his designated agent. The original provision prohibiting painting or otherwise coating or lining a vessel either internally or externally prior to the pressure test for vessels in lethal service remains.

Note that the user also has responsibility to declare whether or not a vessel should be constructed for lethal service, where the term “lethal” is defined in Endnote 65 of Section VIII, Division 1. Also note that Section VIII, Division 2 does not define lethal service, and therefore the user and/or his designated agent have full responsibility to decide whether or not it is acceptable to paint or code pressure retaining welds prior to the pressure test, which should be defined in the Uses Design Specification (UDS).

Editor's Note: This is a sponsored blog post by HSB Global Standards.

Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
Technical Fields - Project Managers & Project Engineers - New Member

Join Date: Jun 2014
Posts: 624
Good Answers: 33
#1

Re: Standards Q&A: ASME’s Changes to Vessel’s Painting Welds

09/15/2016 5:44 AM

This seems pretty stupid, "lethal service" the "user or his designated agent" blah blah blah! Either it should be or shouldn't be, period! It's like calling some crimes "hate crimes" a bunch of BS, either it is a crime or it isn't! Either it should be painted or it shouldn't period. Who determines whether it is "lethal" or not. Either it is going to hold or it won't period. I hope they made a lot of money writing this completely useless 'standard'!

__________________
Hey Isaac, catch! ...oops, that's gonna leave a mark...
Reply
Guru

Join Date: Oct 2008
Posts: 42294
Good Answers: 1662
#2
In reply to #1

Re: Standards Q&A: ASME’s Changes to Vessel’s Painting Welds

09/15/2016 8:12 PM

Not my field but, I tend to agree with you.

The entity that assumes the ultimate risk and responsibility for potential lethality of the vessel should make that determination.

Often, that is not the purchaser.

Reply
Guru

Join Date: Apr 2015
Location: NYC until mid 2015, currently NC
Posts: 756
Good Answers: 8
#4
In reply to #1

Re: Standards Q&A: ASME’s Changes to Vessel’s Painting Welds

09/19/2016 11:24 PM

All those Code committees have to justify their existence.

But I agree with you.

__________________
Good judgment comes from experience, and a lotta that comes from bad judgment.
Reply
Guru
Hobbies - DIY Welding - New Member

Join Date: Sep 2007
Posts: 1601
Good Answers: 57
#3

Re: Standards Q&A: ASME’s Changes to Vessel’s Painting Welds

09/19/2016 10:06 AM

I agree that an authorized authority should be permitted to make an informed recommendation as whether or not to paint. If paint failure would result in a damaging leak, then obviously we may not want paint to act as a sealant. If paint failures can be tolerated, then why not allow the manufacturers to use it? In our business, we use He leak testing. The presence of any organic material (paint, oils, fingerprints, etc.) indicate a leak and are forbidden.

Reply
Reply to Blog Entry 4 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Casper71 (1); lyn (1); Massey (1); welderman (1)

Previous in Blog: The Robotics Market in China   Next in Blog: Standards Q&A: Interpreting ASME’s Post Weld Heat Treatment Requirements

Advertisement