×
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

Asme section viii boilers and pressure vessels ug 135 d-1

Asme section viii boilers and pressure vessels ug 135 d-1

Asme section viii boilers and pressure vessels ug 135 d-1

(OP)
My understanding of ug 125 to 137 is that every PV needs a relief with no block devices between it and the pv except in 135 d-1. I don't completely understand this clause.

Can someone provide an example where block devices can be installed. Not counting appendix m

RE: Asme section viii boilers and pressure vessels ug 135 d-1

If you have several PRV's installed on a manifold for redundancy, each PRV having full relief capacity, these can be fitted with individual isolation valves (for maintenance, test, etc), provided you have a foolproof procedure or mechanical interlock preventing the closure of all isolation valves at once.
Cheers,
gr2vessels

RE: Asme section viii boilers and pressure vessels ug 135 d-1

(OP)
Ok understood

Second question:

Can you have a isolation valve between the relief and supply of the vessel since it isolates the exchanger thus not affecting the relieving capacity.

RE: Asme section viii boilers and pressure vessels ug 135 d-1

Yes, you must have a PRV between the exchanger and the piping isolation valve, unless you can prove the exchanger is protected with piping relief. I am talking about the main piping, not an isolation valve for the PRV alone.
Cheers,
gr2vessels

RE: Asme section viii boilers and pressure vessels ug 135 d-1

(OP)
How could you prove the exchanger is protected by piping relief?

My understanding is that if the exchanger is isolated from the the PRV and energy source, there still could be a fire, unexplained source of heat that could cause the exchanger to explode.

RE: Asme section viii boilers and pressure vessels ug 135 d-1

Perhaps my choice of words is confusing. The exchanger must be protected by PRV, weather is a dedicated nozzle on the exchanger or is a nozzle on the first piece of pipe attached to the exchanger, before the outlet pipe isolation valve and after the inlet pipe isolation valve. If the piping is welded, not flanged to exchanger, the PRV should be a close as practical to the exchanger.

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