×
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!

*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

Slide Gate vs. Globe Valve

Slide Gate vs. Globe Valve

Slide Gate vs. Globe Valve

(OP)
Is there any information available that compares selection of a parallel slide gate valve to a globe valve for isolation in power plant main steam service?

RE: Slide Gate vs. Globe Valve

Hi,
You can't directly compare these types of valves.

Globe valves are generally used for flow control, having a contoured valve seat providing a control characteristic. In service, it is not always possible to close 100% and not considered effective isolation.

A parallel side valve is effectively two gate valves adjacent to each other, and used for safety isolation purposes. Providing "double" isolation between the pressure source and any maintenance activities. In UK (HSE) spec double isolation for pressure systems, you need to check your local code for the exact requirements. Hope this helps.

RE: Slide Gate vs. Globe Valve

hi, the two valves have different construction and hence suggested for different applications.
Globe valves are closing down valves in which the closure membrane is moved squarely on and off the seat. Globe valves are used in applications where a moderate control or regulation of flow and hence pressure is required. it has a control characteristics which shows the flow and pressure drop with respect to percentage opening of the the valve. Since the seating surface is square shaped, it's almost impossible to close the valve fully 100% and since the valve can't be closed fully, whatever be the characteristics of the globe valve (linear or equal percentage or modified linear/equal percentage or hyperbolic), there will always be some leakage and hence 1005 isolation may not be achieved with this valve.

however, gate valves are straight through flow valves which provide positive shut-off with minimal flow turbulence and pressure drop. gate valves may be installed without consideration of direction of flow.A parallel side valve is effectively two gate valves adjacent to each other, and used for safety isolation purposes. They are not recommended for use in partially open, throttling position as excessive noise, vibration, erosion and wear can occur. hence they shall be used in fully open or closed condition and in fully closed condition it can prevent leakage 100%.

in my opinion one shud therefore always have gate valves for isolation purpose.

RE: Slide Gate vs. Globe Valve

Look on the Jordan Valve web site. www.jordanvalve.com
This is a sliding gate valve which I think that you are referring to in your question.
You can on this siste see an electronic presentation of how the sliding gate operates.
This may assist you in making your decision.
It is different from a standard gate valve that you would think of. This design has some distinct advantages ofver the globe style valve as well as a standard gate type valve.

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