×
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

Pressure Reduction in series

Pressure Reduction in series

Pressure Reduction in series

(OP)
We are working on a existing crude oil pipeline which has an existing pressure reduction skid & destination is ship. A new tap off from this existing pipeline downstream of the existing pressure reduction skid goes to a storage tank farm. A new PCV is shown on this tap off for controlling the pressure of crude oil going to the inlet of the floating roof storage tanks. Flow rate varies from 3333 barrels/hr to 9375 barrel/hr. Pressure at inlet of existing pressure reduction skid varies from 800 psig to 1400 psig depending on the flow rate. Distance between existing pressure reduction skid and new PCV is around 800 metres. Will this system of having a PCV downstream of existing pressure reduction skid work properly or will the new PCV and existing pressure reduction skid fight with each other? Awaiting your esteemed response to this query.

RE: Pressure Reduction in series

I think you need to attach a simplified sketch of this system. It is a bit hard to troubleshoot based on textual description only.

Thank you

Dejan IVANOVIC
Process Engineer, MSChE

RE: Pressure Reduction in series

hmmm, 800m is probably enough, but the risk will always be there. It depends to certain extent on the operation. When flowing to the tank farm is this the only flow through the main skid?

If it is then you will need to have a good controls engineer on hand when you commission it. My guess is that you want the secondary PCV skid to act faster than the main one which will then dampen out the variances, but it could be the other way around. These things are really quite difficult to simulate - trial and error on the control loop gain and damping is the only way to fix it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Pressure Reduction in series

(OP)
Thank you for your responses.

RE: Pressure Reduction in series

Unless I'm missing something, I'm not hearing a big problem here. Variable flow, variable inlet pressure, and you've already addressed that once with the variable flow and variable inlet pressure to your main reducing station.

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