Vacuum Jacketed Pipe (VJP) & VIP Cryogenic Systems

Thermal Decoupling Physics

Heat transfer within a vacuum jacket is dominated by three mechanisms: conduction, convection, and radiation. By drawing the annular space to high vacuum (<1×10⁻³ mbar), gas conduction and convective currents are practically eliminated.

• Knudsen number regimes eliminate convective loop transfer
• Multi-Layer Insulation (MLI) mirrors mitigate radiative heat
• Non-metallic low-conduction centering spiders prevent thermal bridging

Phase Purity & Boil-off Prevention

Cryogens like LN2, LOX, and LH2 have extremely narrow enthalpy margins between saturated liquid and vapor. Uninsulated or conventionally insulated pipes induce flash boiling, excessive Boil-Off Gas (BOG), and disruptive two-phase slug flow.

• Preserves subcooling margins up to final point-of-use
• Eliminates cavitation in cryogenic centrifugal pumps
• Reduces electrical footprint of cryogenic re-liquefiers

Outer Jacket Condensation Elimination

In humid cleanrooms, semiconductor fabs, and biobanks, polyurethane or aerogel insulation inevitably degrades, allowing water vapor ingress, mold proliferation, pipe corrosion, and icy hazardous condensation dripping onto equipment.

• Outer jacket stays at ambient room temperature
• Zero atmospheric moisture ingress into the vacuum annulus
• Maintenance-free austenitic stainless steel construction

Static Vacuum Insulated Piping

Each pipe spool is evacuated to high vacuum in the factory, baked out under thermal desorption protocols, sealed with dedicated evacuation valves, and sustained with chemical getters.

• Zero Operating Energy: Does not require field vacuum pumps or operational monitoring equipment.
• Autonomous Spools: Damage or vacuum loss in one spool does not compromise neighboring runs.
• Getter Technology: Incorporates advanced barium and palladium getters to continuously scavenge residual hydrogen and outgassed molecules over 15 to 20 years.
• Ideal Application: Semiconductor fabs, cleanroom laboratories, molecular beam epitaxy (MBE), biobanks, and regional cryobanks.

Dynamic Vacuum Insulated Piping

The annular vacuum spaces of multiple piping sections are interconnected through vacuum jumper hoses and continuously or intermittently evacuated using high-vacuum turbomolecular pumping units.

• Field Serviceable: Vacuum can be repeatedly restored on-site without shipping modules back to the factory.
• Lower Initial Fabrication Cost: Less stringent factory bake-out cycle times and reduced reliance on expensive getter packs.
• Active Monitoring: Integrated Pirani/Penning gauge controllers provide real-time alarm outputs into plant DCS / SCADA systems.
• Ideal Application: Large air separation units (ASU), aerospace rocket launch pads, LNG terminal ship-to-shore bunkering, and extensive outdoor utility lines.

Internal Axial Bellows

Hydroformed multi-ply stainless steel bellows are integrated into the inner liquid transfer pipe. They absorb cyclical axial shrink-stretch fatigue without transmitting destructive bending loads to outer structural welds.

Thermal Decoupling Spiders

Radial support spiders engineered from high-strength G-10 glass-epoxy or proprietary ceramic polymers separate the internal cryogenic pipe from the outer jacket, maintaining exact concentricity with fractional conduction heat ingress.

Outer Jacket Protection

Every spool incorporates an ASME-compliant vacuum pump-out port integrated with an internal rupture disk and spring-loaded relief plate to prevent catastrophic over-pressurization if inner pipe leakage ever occurs.