1. Temperature Range
Accurately determine the minimum/maximum temperatures-the critical parameters for selection.
Material performance requirements vary significantly across cryogenic ranges.
Example: For -40°C to -100°C environments, carbon steel becomes brittle; stainless steel/nickel alloys with superior cryogenic toughness are required.
2. Pressure Rating
Define system working pressure and potential peak pressure. The valve's nominal pressure must ≥ system max working pressure.
Example: For a 1.6MPa cryogenic system, select valves with ≥1.6MPa nominal pressure.
3. Body Materials
Common options:
Stainless steel (304L/316L): Excellent cryogenic toughness & corrosion resistance for most applications.
Nickel alloys (e.g., Monel): Superior performance in extreme cryogenic/corrosive environments.
4. Disc Materials
Match the valve body material (stainless steel/nickel alloy recommended).
Surface treatments (e.g., polishing) reduce fluid resistance and enhance sealing.
5. Sealing Materials
Critical for low-temperature sealing performance:
PTFE: Chemical stability and cryogenic compatibility for most media.
Rubber (e.g., EPDM): Good elasticity but narrower temperature range.
6. Standards & Certifications
Ensure compliance with API, ASME, GB, etc.
Verify cryogenic certifications (e.g., fireproof/explosion-proof ratings).
