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

Related Articles


Rising stem VS OS&Y valves

Rising stem VS OS&Y valves

Rising stem VS OS&Y valves

Hi ,

is there any difference between the Non rising stem valve & OS&Y valves ? i see some time some ppl used rising stem description and others use OS&Y valve description


RE: Rising stem VS OS&Y valves

In a Rising Stem (RS) the thrust bearing is inside the valve and the operating wheel rises as the valve opens, the bearing is lubricated by the fluid inside the valve.

Open Yoke and Stem (OS&Y) has the thrust bearing outside the valve so may require external lubrication, but it is very easy to see the valve position. This valve also takes more room to operate. The operating wheel does not change vertical position at the valve is operated.

Non rising stem (NRS) does not indicate the position of the valve and is typically buried, this valve remains the same size no mater what the position is nor does the operator wheel or nut move vertically. The thrust bearing is lubricated by the fluid.


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