×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Shim stack as per API RP 686

Shim stack as per API RP 686

Shim stack as per API RP 686

(OP)
Hi..
I need some help regarding shim requirement/ shim stack stated on chapter 7 point 5.4.2
It is tells us only one 3mm or thicker shim per mounting foot is allowed.
Is that mean we really need only one shim with thickness 3,4,5 and so on??or if we had 2mm shim, it could be used as the "thicker" one instead of 3 mm??
For example if we need to shim 4 mm,could we use shim stacked 2 +1 +1? Because in my opinion 2mm is the thicker one..or is it ok to use 2+2??

And about shim sandwich..which is correct the thinner shim in between or the thicker?

Thank you,
Firmans

RE: Shim stack as per API RP 686

I'm not familiar with the exact spec you're talking about, but I've seen similar specs and I believe I know what they're getting at.

Quote:

Is that mean we really need only one shim with thickness 3,4,5 and so on??
You can have a maximum of one shim in that size range. Any other shims up to the max total have to be smaller (I believe the max total is 3 or 5).

Quote:

or if we had 2mm shim, it could be used as the "thicker" one instead of 3 mm??
sure.

Quote:

For example if we need to shim 4 mm,could we use shim stacked 2 +1 +1? Because in my opinion 2mm is the thicker one..or is it ok to use 2+2??
either is ok

Here is a better example: if you are trying to fill 7mm, you can do 5+1+1 but you can't do 3+3+1. (because the latter option has two shims of 3 or more).

=====================================
(2B)+(2B)' ?

RE: Shim stack as per API RP 686

(OP)
How about if we use 2+2+2+1?

RE: Shim stack as per API RP 686

I am looking at the 1996 rev of API 686 (the latest I have)

Quote (API 686 (1996))


5.4.2 SHIM REQUIREMENTS
5.4.2.1 The maximum allowable number of shims under any equipment support foot is five.
5.4.2.2 ..... Only one 3-millimeter (0.125-inch) or thicker shim per mounting foot is allowed.
So yes you can use 2+2+2+1 since you would have 0 at 3mm or more, and 4 total.
You cannot use 2+1+1+1+1+1 since you would would have 6 shims total - exceeding the max total shims (5).
You cannot use 3+3+1 since that would be two 3 mm shims.

=====================================
(2B)+(2B)' ?

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


Resources

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