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.

MortenA (Petroleum) (OP)
3 Apr 06 4:03
I have often used a closing time of max. 20 seconds for ESD valves. Are there anyone here who knows a reference for this value (closing time for an ESDV?)

Best regard┬Ęs

Morten
Helpful Member!  JLSeagull (Electrical)
3 Apr 06 7:31
In the US offshore industry the requirement is to close within 45 seconds including the system response time (consider in case of pneumatics).  This is a rule applied by the Department of Interior Minerals Management Service is covered by API RP 14C Recommended Practice for
Analysis, Design, Installation, and Testing of Basic Surface Safety Systems for Offshore Production Platforms, Appendix C - Support Systems C.2.1.4.  "The time it takes for any safety device (e.g. PSH, BSL, ESD station, etc.) to effect component or platform shutdown should not exceed 45 seconds."
MortenA (Petroleum) (OP)
3 Apr 06 7:38
Brilliant JLSeagull

Thank you

Morten
Ashereng (Petroleum)
3 Apr 06 12:35
I would have thought that the closing time varied, by size, application, etc.

I have seen a huge volume bottle to close a valve (I think 6", maybe 4") in little over 5 seconds.

I have seen others where 45 seconds probably is more than enough.

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

JLSeagull (Electrical)
3 Apr 06 12:49
Actual times are far different than the API requirements.  Shutdown valves three-inch and smaller close quickly.

My casual observation is that the closing time for ball valves requires about one second per inch.  As you approach the 24-inch size you should be using quick exhaust devices to meet the 45-second rule.  Also, the actual process pressure impacts the closing time.  A 36-inch full port ball valve may close within less than 45-seconds during commissioning then actually close in 75-seconds against 1200 psig.


API RP 14C lacks opening time criteria.
stanier (Mechanical)
3 Apr 06 21:06
Should one consider the transient pressure results in closing the ESD in a certain time? The philosophy should be that no safety measure should create an unsafe situation. A fast closing ESD may cause a pressure transient that could rupture a pipeline.

It comes down to a risk management situation. WHat is the likelihood adn consequence of an action. Engineering design will follow from the analysis.

MortenA (Petroleum) (OP)
4 Apr 06 3:40
I am familiar with a NFPA rule of thum that says 1-1.5 sec/"

Sometime "worst case" is a fast closing time (surge e.g.) sometime the long closing time may be a problem (overpressure vented inventory etc.).

But the ansver from JLSeagull was what I was looking for (just couldnt remember the reference).

Best regards

Morten

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