×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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.

Students Click Here

Orifice Sizing Equations

Orifice Sizing Equations

Orifice Sizing Equations

(OP)
Hi all,

Can someone guide me to a reliable technical resource that has equations for calculating temporary pressure loss, permanent pressure loss, max velocity across an orifice?

I’ve seen some equations in the past that take into account orifice details such as thickness, sharp edge etc but I cannot find them. Any help is greatly appreciated.

My fluid is liquid but it would be good to have a reference for gas orifice sizing as well.

Cheers

RE: Orifice Sizing Equations

This is an FAQ for choked flow through an orifice. https://www.eng-tips.com/faqs.cfm?fid=1201

If you're doing it for measurement there are specific calcs for that which normally limit DP to 1000mbar

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Orifice Sizing Equations

hi, a search with your favorite engine should be the ultimate resource.
Pierre

RE: Orifice Sizing Equations

(OP)
Thanks guys

RE: Orifice Sizing Equations

For natural gas, I used the AGA Report No. 3 or Orifice Metering of Natural Gas and Other Related Hydrocarbon Fluids— Concentric, Square-edged Orifice Meters
Part 1: General Equations and Uncertainty Guidelines

I size the orifice dP for a max orifice dP at 100-inH2O, simply to minimize pressure loss and noise generated. Check orifice dP at min/norm/max flows and size orifice accordingly.

Fyi, I stumbled across an orifice plate at 4" in 8-inch pipe with 450-inH2O dP across the orifice. Noise was absolutely terrible. Increase plate size to max beta size and a "normal" conversation could be had in the gas turbine/compressor enclosure.

RE: Orifice Sizing Equations

Quote (oilman11)

Can someone guide me to a reliable technical resource that has equations for calculating temporary pressure loss, permanent pressure loss, max velocity across an orifice?
See chap. 4 Idelchik's Handbook
https://www.nrc.gov/docs/ML1220/ML12209A041.pdf
In case if you are looking for a calculations of orifices having design the same as flow measuring orifices then you should consult your instrumentation&ocontrol engineer for codes applicable in particular project. You might take a better comments if share with us what kind(s) of orifices and how you are going to use those.

RE: Orifice Sizing Equations

First question is: Is it a restriction orifice or an orifice for measuring flow?

First one: Use something along the API 520 for a PSV
Second: Theres an ISO standard (and many other possible) - although i cant remember what no.

There is a lot of difference between the two methods mostly due to the required accuracuy i would think.

--- Best regards, Morten Andersen

RE: Orifice Sizing Equations

Here is a link to a calculator:

Link

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! Already a Member? Login



News


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