Shim size requirement

[tranduyquang]

I know API states how many shims and total thickness for shim packs. But no clues about the shim size. So, could somebody advises me what is the Shim size requirement using for the API610 pump? The shim shape should be matched to equipment foot or not?

 

[electricpete]

Stan Riddle wrote some thoughts here:

https://vibralign.com/shaft-alignment/size-shims-use/

(he used to be a poster on the old reliability-magazine.com and subsequent maintenanceforums.com ... haven't heard from him in awhile).

Ludeca has a table 3 here for NEMA-frame electric motors which I think came from a shim manufacturer

https://www.plantservices.com/assets/Media/1410/machinery-alignment-shimming.pdf

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

 

[quadtracker]

Many manufacturers that assemble compressor and pump skid packages are using SKF vibracon - adjustable chocks, rather than shims under the motor or engine foot. They support angular soft foot much better than stacking shims. check out SKF Vibracon on google to get full understanding.

 

[JS_]

Years ago, I had a few rules. Using a little common sense

(1) everything must be clean.

(2) shims = 80% of the foot contact area.

(3) No more then five shims.... Sometimes soft foot will take more. If the feet or base is really out of spec fix before continuing.

(4) Shim pumps using either a .125 or .250 ... The reason and example: You don't know where the manufacture's center-line is exactly the tolerance could be plus 0 or minus .0625 or more. If you have to replace the unit and it is on the plus side of it you waste more time messing with the driver.

SKF vibracon chocks can prevent a few headaches later on....

 

[electricpete]

SKF vibracon chocks can prevent a few headaches later on....

https://www.skf.com/us/products/maintenance-products/alignment-tools/adjustable-chocks/index.html

Those look interesting. Unfortunately for an existing application, when you put these under the motor you'd have to move the pump up by the same amount, which would mean redoing some piping. Even for a new application, I'd wonder about the effect in reducing the machine's resonant frequency.

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

 

[quadtracker]

I have used them on big gas drive engines on recip compressors packages no issues these engines weigh over 15000 lbs over 1400 hp. The bottom of the vibracon can be machined to adjust height plus using the threads for adjustment.