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Date: Thu, 23 Oct 1997 12:24:40 -0400
From: Alex Varouxis <alexv@er*.co*>
Organization: Associated Design and Manufacturing Company
To: Pedro Neves <a2376@le*.si*.ua*.pt*>
CC: techdiver@aquanaut.com
Subject: Re: Viton
Pedro

The Use of Butyl O’rings  is ok with some Oxygen applications, Viton my
be more compatible for diving due to cold water. Neoprene orings are not
compatible the oxygen will deteriorate the Oring.   

Below is Information from the Parker O-ring handbook publication # ORD
5700 and Apple Rubber Products handbook. Parker can be reached at (606)
269-2351 apple at (800) 828-7745 another good source for O-rings is 
Precision Associates (612) 333-7464 the have one of the best O-ring
catalogs I have seen.  If any one would like me to fax them the Chemical
compatibles table for O-rings from Parker and Apple leave me you fax
number

FLUOROCARBON RUBBER (FKM)
Typical trade names:

Fluorel			3M
Kalrex (high temp)	E I duPont
Kel-F			3M (formerly Kellogg)
Viton			E I duPont
Technoflon		Montedison  USA

ASTM   D1418 Designation: FKM
ASTM D2000/SAE J200 Type Class: HK


Fluorocarbon elastomers were first introduced in the mid 1950's.  Since
then they have grown to major importance in the seal industry. Due to
its wide spectrum chemical compatibility and temperature range and its
low compression set, fluorocarbon rubber is the most significant single
elastomer development in recent history.
Its working temperature range is considered to be -15º to +400º F (-29º
to +204º C), but it will take temperatures up to 600º F (316º C) for
short periods of time, and Du Pont's Kalrez is normally recommended up
to 500º F (260º C). On the low temperature end, Parker's compound
V835-75 will seal down to -40º F (-40º C) in a static seal. Though the
standard compounds have been known to seal at -65º F 
(-54º C) in some special static applications, the normal low temperature
limit is -15º F (-26º C).
Special formulations having extra chemical resistance are also
available, and new types are being developed constantly.
Fluorocarbon o-rings should be considered for seal use in aircraft,
automobile and other mechanical devices requiring maximum resistance to
elevated temperature and to many functional fluids.

FKM is recommended for:
Petroleum oils
Di-ester base lubricants (MIL-L-7808, MIL-L-6085).
Silicate ester base lubricants (MLO 8200, MLO 8515, OS-45.)
Silicone fluids and greases.
Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene).
Selected phosphate ester fluids.
Acids.

FKM is not recommended for:
Ketones (MEK, acetone).
Skydrol fluids.
Amines (UDMH), anhydrous ammonia.
Low molecular weight esters and ethers.
Hot hydraulic or chlorosulfonic acids.

Limitation:  Fluorocarbons are not recommended for exposure to ketones;
amines; low molecular weight esters and ethers; nitro hydrocarbons; hot
hydrofluoric or chlorosulfonic acids; or Skydrol fluids.  They are also
not recommended for situations requiring good low temperature
flexibility.
Another viton experiment is:  




Pedro Neves wrote:
> 
> I heard that viton o-rings aren't suitable for O2 service. The reason for
> this is that aparently when a viton o-ring burns it releases toxic gases
> (fluorine and chlorine compounds). Can anyone confirm this? And if its
> true, are there any other solutions for O2 service material?
> 
> Thanks in advance.
> 
> Pedro Neves
> Pedro A. Neves                                  e-mail: a2376@le*.si*.ua*.pt*
> Centro de Mergulho Cientifico                   Fax: +351-89-818 353
> U.C.T.R.A.
> Campus de Gambelas
> 8000 Faro
> Portugal

-------------------------------------
Alex Varouxis
Associated Design and Manufacturing Co.
(V) 703 549-5999 (F) 703-548-0919
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