×
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

control valve basic question

control valve basic question

control valve basic question

(OP)
when a control valve is specified as a 12X8  or 4X2 what do these two dimensions mean. One is the line size and the other? thank you

RE: control valve basic question

My guess is that your looking at the reducer. Control valves will often have a reducer/expander before and after them so that they can use a smaller valve and have greater control.

RE: control valve basic question

(OP)
sorry my first post was not so clear, the line size is 8in in and out, but for the body size its listed as 4x2  special meaning?  

RE: control valve basic question

(OP)
fisher ewt body to be exact

RE: control valve basic question

I don't have a catalog handy.  I think that the EW series such as the EWT are cage style globe pattern valves with expanded end connections.  The larger number applies to the line size and the smaller number applies to the body size.

The EWT is likely balanced with about FCI Class IV shutoff.  I think that these are in-line with larger body expanders to accommodate either noise or cavitation control trim.  One of the specialty valve bodies was canted about 30 degrees but I don't think that it was the EW series.  The expanded end valves apply to high pressure drop and high velocity applications with larger pipe size due to the velocity.  It is common to have the piping a few sizes larger than the control valve but where the reduced piping velocity is still reasonable.

RE: control valve basic question

typically the first number is the body size and the second the trim size. The trim size is the diameter of the the actual moving parts or "cage" in the valve.  

RE: control valve basic question

dcasto is correct.

A 4 x 2 EWT valve is a 4" body with a 2" trim. (This is nominal, and not exact size.)

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of Eng-Tips Forums?

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