1)NBR:
NBR is the copolymer of butadiene and acrylonitrile polymerize
at the suspend liquid.
2)HNBR: Its
properties is better than NBR, applied temperature from -40
to 150 degree centigrade, it is better exist in H2S than Vtion
does, and exist better in oil than NBR does.
3)Fluoro rubber:
Fluoro rubber is the polymer which contents F. The fluoro
rubber of Chinese code are two types: F-23 which equivalent
to Kel-F and F-26 which equivalent to Viton. Fluoro rubber
has the excellent properties such as heat resistance, matches
well with oil, anti-corrosive and vaccum resistance, but fuoro
rubber is not suitable in the liquids such as ketone and este
and cold resistance is not good, huge change on permanent
deform after it was pressed.
4) EPM: EPM
is the polymer of ethene and propylene£¬include terpolymer
and binary copolymer. Normally, Trisun use EPDM.
5) Siliocn Rubber:
Silicon rubber is composite by organic Si and hydrocarbon.
Good performance on heat and cold resistance, small change
of permanent deform after it was pressed£¬excellent on electric
spread. The disadvantage are worse tear and wear resistance
at the average temperature than other material rubbers, and
it can not be used in the mineral oil with lower boiling point,
it will be easy decomposed at the environment with high pressed
water steam.
6) PTFE: It
has a wide application range of temperature from -150 to 250
degree centigrade, extremely low friction coefficient and
self-lubricate£¬it will not felt on its surface£¬its chemical
characteristics are stable. The only matter which can corrode
this kind of material is melted alkali metal and the F element
in high temperature and pressure. It will changed in any temperature
under the effect of burthen, when the temperature above 343
degree centigrade it will decompose and release poison smoke.
7) CR, HR and
epichlorohydrin rubber etc. also can be used for secondary
seal ring.
8) Soft carbon,
adbestos and the composited material of rubber and plastic
also can be used in secondary seal ring but in high temperature
environment.
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