×
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

Steam PSV Pipe

Steam PSV Pipe

Steam PSV Pipe

(OP)
What are the guidelines for sizing steam PSV pipe?

Should I take same approach as for sizing steam piping (since same median will flow through) or there are some other requirements?

Thank you.

RE: Steam PSV Pipe

You also need to consider the PSV, i.e. too much back pressure on the valve will affect its performance. It is usual to limit back pressure to 10% of the PSV set pressure (depends also on what type of PSV is to be installed).

Cheers,
John

RE: Steam PSV Pipe

FREAKMEOUT:
REFER TO ASME B31.1 APPENDIX II NONMANDATORY RULES FOR THE DESIGN OF SAFETY VALVE INSTALLATIONS

The size and length of the discharge pipe from a steam pressure safety valve is critical.
As the steam leaves the valve it expands. As it moves down the pipe it continues to expand so the velocity increases.
If the velocity reaches Mach 1 the flow rate will be what is called "choked flow". If this flow rate is less than the capacity of the relief valve the require relief flow cannot be attained. The associated equipment could then over pressure and explode.

You must calculate the equivalent length of pipe at which the velocity reaches mach 1. The actual equivalent length of discharge pipe must be shorter than the length required to reach mach 1.


Regards,
D Landis

RE: Steam PSV Pipe

(OP)
Thank you.

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