How do you dimension o-rings?

[dongfang]

Hi,

Some people hate o-rings. I love them... but I´m not always sure I treat them right

How do you guys determine the thickness of the o-ring to use? I suppose the "correct" thickness depends on material tolerances (for the rings to bridge across), the required friction and whether the application is static or dynamic.

I seem to often end up at d_1 = 1/10 of the diameter of the pipe the ring is sitting on for dynamics (piston rings etc.), and 1/15 to 1/20 for static. Both for PVC fittings.

Any opinions; could I use larger / smaller? I can get every metric, US and Swedish standard size...

Regards
Soren

[cdheller]

http://www.parker.com/ead/cm1.asp?cmid=771&lang=SV
is the Swedish start page
they probably have the fallowing stuff in Swedish or whatever lingo you do best with (they are worldwide)

_______________________________________________________________________________________


""Since 1994, Parker O-ring Division's inPHorm (pronounced in'-form) has been the ultimate desktop tool for O-ring design and material selection. ""

http://www.parker.com/ead/cm2.asp?cmid=2973




""The Bible of the sealing industry. Everything you ever wanted to know about seal design, material selection, and failure analysis.""

http://www.parker.com/o-ring/Literature/ORD5700.pdf


the first discription and link is for a free oring program.
mostly you point and click your way through selections with some size inputs

for example on gland selection you can choose between
o-ring only, floating pneumatic piston seal, industrial reciprocating (female or male,) industrial static (female or male) , industrial tube fitting boss seal .
also the military version of each of the above
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metric or inch


the above choices have application diagrams and a reference button for your benefit .

if you know some of the info it'll figure out the rest.
and give you dimensions or if applicable a dash number

you don't have to to use the program but you can read thru the included references ,index's, and o-ring users guide

if you still have a hankering for more info the second link is around 300 pages of pdf book .,, unless your planing a career in orings or are real curious It's probably overkill.