Automotive Air Conditioning Information Forum (Archives)

Provided by

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

Sizing o-rings

hawthorne90250 on Sun January 18, 2009 3:08 PM User is offline

Country of Origin: Germany

I am trying to restore my A/C on a Grey market 84 Mercedes 300D. This car came without A/C and was added later. My question is i am converting it to R134a with new O-Rings fittings and i am trying to figure out what size o rings to use at the hook up points, expansion valve, receiver/dryer and so on, i know the ID of the seal is the one that fits over the fitting, but i am afraid that the OD plus thickness might be too small /big for the components. Anyone know what i should be looking for.

HECAT on Mon January 19, 2009 5:31 AM User is offline

Measure the fixed ID and OD of the physical location where the o-ring is to be placed, this is the "nominal" dimension and the size o-ring you will need to request or order. An o-ring designed to seal in a 1/8 inch deep groove will actually have a larger cross section (i.e. smaller ID, larger OD) and this will be the "actual" dimension. The application info will not only dictate the material used but also the engineered oversize (actual dimension) necessary to achieve the desired compression into the groove (nominal dimension) to provide the seal at the pressures expected in that application.


HECAT: You support the Forum when you consider for your a/c parts.


Edited: Mon January 19, 2009 at 6:05 AM by HECAT

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.