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Omniseal® Spring-Energized Seals
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Launch Vehicle Cryogenic Valve Polymer Seals

    Kha Le
Space Cryogenic Extreme Environment
Launch Vehicle Cryogenic Valve Polymer Seals Case Study

Environment

To control the flow of cryogenic propellants such as liquid oxygen, liquid hydrogen or liquid methane on launch vehicles, cryogenic valves are used within these rockets. To meet the industry’s goals of safety and success in these critical fluid control systems, there are requirements set for not only the launch vehicle manufacturer but also the designer of these valves and their components (e.g., sealing solutions). All parties must have knowledge of operating conditions such as pressure ranges, temperature ranges, speeds, loads, and installation procedures.. Failure in these valves during launch could have catastrophic results.

Challenge

In this dynamic application, sealing is quite challenging due to the cryogenic temperatures of fluids and the resulting dynamic motion. For solenoid valves, in particular, a key requirement for the seal and the jacket material is low friction. For polymer seals and most other seal types, the friction usually increases due to shrinkage of materials. Why is this mission-critical? Friction control ensures that the valve actuator will operate according to the valve planned lifetime. In fact, a precision sealing solution grants the correct opening and closing of the valve; thus, regulating the amount of fluid circulating and the necessary functionality in the launch vehicle combustion and engine.

Rocket Cryogenic Valve Actuator Seal
Omniseal ATS Metal Band Seal

Solution

The Omniseal® ATS (Anti-Thermal Shrinkage Seal) is a custom-design sealing solution engineered to handle the natural shrinkage of polymers used in seal jackets at cryogenic temperatures. This metal band is added between the jacket and the spring to provide consistent sealing on the outer diameter (OD) of the seal, which tends to suffer due to shrinkage of the polymer jacket.

By using this critical precision metal-band, the seal can meet the stringent leakage requirements that are typically around 0.1 to 0.01 sccs while not generating excessive friction on the reciprocating or rotating shaft.

Protect your cryogenic propellants by using the Omniseal® Anti-Thermal Shrinkage Seal

Benefits

  • Friction control
  • Low leakage in cryogenic conditions
  • Limits polymer shrinkage effect
Tags: Space Cryogenic Extreme Environment