×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Attachment welds for lethal service vessel

Attachment welds for lethal service vessel

Attachment welds for lethal service vessel

(OP)
Dear all,
Can fillet weld without full penetration for internal and external attachments (such as tray support rings, platform support clips) be used for lethal service vessel ?

RE: Attachment welds for lethal service vessel

An odd question.
Why do you think an appropriately designed fillet weld using an appropriate filler material and PWHT as required could not be used?

Existing tank and new weld for new attachment?
Existing tank, new weld to repair a failed attachment?
New design tank with new fillet weld?

RE: Attachment welds for lethal service vessel

What racookpe said. The requirement for 100% full-penn welds is for pressure-boundary, pressure retaining items. Your brackets have nothing to do with pressure retention. But install everything you can think of, and maybe a couple of spares prior to PWHT. Adding something 'later' to a Lethal Service vessel is brutally expensive.

RE: Attachment welds for lethal service vessel

(OP)
There are certain services and/or material that full penetration weld for attachment is not just preferred, but mandatory by many companies that put into their own specs, such as hydrogen service, wet sour service, cyclic service, or low alloy material in high temperature service.

I am seeking the opinion if lethal service shall be doing the same to avoid traping the lethal content in crevice that may be inhaled during maintenance or repair in the future. I do see a thread saying using integrally reinforced nozzle for lethal service, and for sure nozzle has to be full penetration weld. By the same token, shall at least all internal attachment welds be full penetration ?

Whoever who has experience in design and purchase lethal service in the past, please advise.

RE: Attachment welds for lethal service vessel

I'm new in this forum so first of all, hello to everybody peace

With lethal service all welds that connect internal plates to the clad/w.o. shall be full penetration. This is mandatory.
Personally, I would suggest to perform always full penetration welds on all attachments (internal or externals) to the pressure vessel body.

RE: Attachment welds for lethal service vessel

(OP)
Paulshark,

This is not neccessary to be a cladded vessel for lethal service. Is your point still valid for using full penetration weld for CS parts to CS vessel ? Where can I find a document saying full penetration shall be used ? Thanks.

RE: Attachment welds for lethal service vessel

jtseng, the reason you are having a hard time finding that prohibition is that it does not exist. Nothing 'magical' about Lethal Service, just get all vessel details approved by your AI *prior* to starting construction, including your proposed NDE methods and locations.

RE: Attachment welds for lethal service vessel

My experience was on hydrogen and sour service only.
For a carbon steel vessel on lethal service have firstly a look a the code, and then check the client specifications.
If no restriction are present go further with the weld you desire.
As I remember ASME doesn't have rules for welds on structural attachments.

greetings

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources