Contact US

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

Concept of operating cases- compression

Concept of operating cases- compression

Concept of operating cases- compression


As you know, generally equipment datasheet are specified in terms of operating cases. For example a centrifugal compressor datasheet may have few cases (summer, winter, normal, rated, etc.) specified.
The API 617 recognizes theses operating conditions specified and includes requirement that apply to these operating conditions (example Maximum Allowable Working Pressure based on maximum discharge pressure between all operating cases, motor rated power calculations, etc).

From my experience, the machinery designer normally verifies the equipment based on the operation (example: looking maximum operating speed) ; But there are situations based on API 617 where only the operating cases will be considered to verify the design unless more stringent rules are applied for instance due to manufacturer's policies.

My question is how true is that on the field to have discrete operating conditions ? If you specify a machine with say 4 operating cases. Is that true that the machine on the field and the process will make the machine to operate exactly or in the vicinity of the operating cases as specified ? Its seems hard to believe so, I would expect the operation to be varying between the specified cases either to transition from one case to the other or simply operate continuously with significant offset to the case as specified. In short: having the design and operation verified against a set of specified cases seems to be theoretical and an idealization.

What is your experience on site or in the field ?

RE: Concept of operating cases- compression

Is that true that the machine on the field and the process will make the machine to operate exactly or in the vicinity of the operating cases as specified

It is true, if your control system (or operating staff) is good enough. The system should always be operated between design cases. Design cases are often set by practical limits such as well flow, city demand on the year's average coldest day, max and minimum environmental temperatures, max/min downstream pressures, etc. If anything changes, you'll need some control to keep the compressor within your limits, otherwise it will find its own running position, which may not be appropriate for your needs.

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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