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!

*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.


API 2000 discharge coefficients for preliminary psv sizing

API 2000 discharge coefficients for preliminary psv sizing

What discharge coefficients are recommended for low pressure tank PSVs when designed to API 2000?

This is for preliminary sizing. Service is gas. For API 520 I'd use 0.975 but not sure this applies to an API 2000 psv.


RE: API 2000 discharge coefficients for preliminary psv sizing

I usually just use the capacity charts from Enardo or Varec or others. I might curve fit them to automate the calculation process. Then the discharge coefficients are unimportant to me.

RE: API 2000 discharge coefficients for preliminary psv sizing

In the old days, we used an orifice discharge coefficient of 0.5 for preliminary sizing. We also used a "rule of thumb" that the sizing pressure had to be 2X the set pressure to guarantee the pallet was wide open.

Nowadays, in the 6th Ed. (Nov. 2009) of API 2000 I glanced at, they show a graph of discharge coefficient (Y) versus absolute pressure ratio (X) of inlet P / outlet P. For X from 0.5 to 1.0, Y ranges from 0.825 to 0.65, respectively. This is from the curved labeled valve discharge coefficient for published capacity.

Good luck,

To a ChE, the glass is always full - 1/2 air and 1/2 water.

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!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close