Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

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

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

Chemical plant design & operations FAQ

FAQ

What is turndown and rangeability?
Posted: 5 Nov 03

Turndown and rangeability is usually associated with control valves. The definition of these are (from Perry):

                       maximum controllable flow
Rangeability R=--------------------------------
                       minimum controllable flow

                           normal maximum flow
Turndown ratio T=-----------------------------------
                           minimum controllable flow

Generally valves are designed so that T=0.7*R where R is between 20 and 50.

This definition complies with the ISA standard.

Turndown is often used not only in connection with control valves but also as a more "global" parameter e.g. for whole plants.

Back to Chemical plant design & operations FAQ Index
Back to Chemical plant design & operations Forum

My Archive

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