Brief Overview of Cryogenic Liquid Nitrogen Breakaway Valves

(Content Translation)
Cryogenic Liquid Nitrogen Breakaway Valves (also known as Emergency Release Couplings for LN₂) are specialized safety devices designed for ultra-low-temperature applications involving liquid nitrogen (-196°C).

Key Features:

1. Function:

   • Automatically severs and seals transfer lines during emergencies (e.g., hose/pipe over-pull, equipment displacement) to prevent uncontrolled release of LN₂.

2. Technical Requirements:

   • Cryogenic Materials: Constructed from stainless steel (e.g., 316L) or alloys resistant to thermal brittleness at -196°C.

   • Vacuum Insulation: Often integrated with vacuum-jacketed pipes to minimize heat ingress and prevent ice formation.

   • Sealing: Low-temperature compatible seals (e.g., PTFE, metal-to-metal) ensuring leak-tight closure after activation.

3. Activation Mechanisms:

   • Mechanical Breakaway: Triggers when excessive force (tension/bending) is applied.

   • Manual Emergency Release: Optional pull-cable for remote activation.

4. Applications:

   • LN₂ storage tank loading/unloading systems.

   • Cryogenic transport trucks and pipeline connections.

   • Laboratories and industrial gas supply networks.

5. Critical Standards:

   • Complies with ISO 21028 (cryogenic vessel safety) and ASME B31.3 (process piping guidelines).

Note: These valves are single-use devices—must be replaced after triggering. Regular inspection for frost damage, seal wear, and structural integrity is essential to ensure reliability.

(Terminology: "Breakaway Valve" is used for general clarity; "Emergency Release Coupling (ERC)" is the technical term.)