What is the best option for replacing o-rings if you have several options of various ratings/materials (Duro 70/90, Viton, Urethane, etc) ? Is that a general rule what is preferred over if you want good low/high temperature material, high pressure, lots of abrasion, compression, elasticity, etc? Basically, I want to buy the most durable option so I do not need to replace the o-rings that often.
For example if the manufacturer calls for Buna 90 for a pellet-probe (high abrasion) what would you upgrade to, a Urethane 90? What about a Buna 70 seal for a CO2 valve or piston? Use urethane 70 because more durable and better low temperature elasticity? 70 is softer than 90, but is there a rule when to switch over to 90 from 70?
Recommended Better Best
Buna 70 => Viton??? => Urethane ????
For example if the manufacturer calls for Buna 90 for a pellet-probe (high abrasion) what would you upgrade to, a Urethane 90? What about a Buna 70 seal for a CO2 valve or piston? Use urethane 70 because more durable and better low temperature elasticity? 70 is softer than 90, but is there a rule when to switch over to 90 from 70?
Recommended Better Best
Buna 70 => Viton??? => Urethane ????