×
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

Startup Purge for new gas main

Startup Purge for new gas main

Startup Purge for new gas main

(OP)
We have been asked to perform a startup for a new natural gas line consisting of 2000' of 12" pipe and 1800' of 6" pipe. Are there purging requirements or standard procedures for this type of distribution system? The operating pressure will be 25psi. The system has already been pressure tested to 100psi to meet the owners specifications.

Would static electricity be a concern if there are ball joints in the line for expansion and contration since this pipe is located on a roof. (a really big roof)

RE: Startup Purge for new gas main

Yes of course you must purge the line.

Are the ball joints insulated?
If you want to ensure conductivity, bond across them.

**********************
"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic
"Note: Make that 99.99% for pipeline companies" - http://virtualpipeline.spaces.live.com/

RE: Startup Purge for new gas main

There is a manual that is published by the AGA (I think) that discussed purging times and pressures.  I don't have a copy available right now, so I can't give you the number.   

You may want to check it out.  

RE: Startup Purge for new gas main

The AGA Purging Principles and Practices manual is the single worst document that the AGA (a fine organization, by the way) ever published.  Following the recommendations of that book creates some very high-risk conditions.

As far back as statistics are avaiable, the Oil & Gas industry has had about one purge-related fatalaty per month somewhere in the world.  Getting this wrong is pretty high risk, but the safety mavens have consistently ignored the potential.  If you are interested, I have a document on my web page (follow the link below and go to "samples") that a group of us wrote a few years ago to provide guidance to people writing purge procedures.  It is a bit long, but the topic is very large.

David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

"Everyone is entitled to their own opinion, but not their own facts"  Patrick Moynihan

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