Vacuum-Jacketed Cryogenic Piping Upgrade for an Active Facility

Location: United States

Industry: Research and Laboratory Facilities

Service: Cryogenic piping and specialty mechanical construction

The Situation

An active operating facility needed a vacuum-jacketed cryogenic piping upgrade after sections of its liquid-nitrogen distribution system developed icing and loss-of-vacuum conditions. The owner needed the compromised piping repaired, a new controlled connection installed, and the upgraded system integrated with the existing distribution network.

Completing the work required careful shutdown planning, specialty fabrication, and close coordination around existing building systems. The project also required clean work practices and controlled restoration because surrounding operations remained active.

The Challenge

Liquid nitrogen operates at extremely low temperatures, so the integrity of both the inner process line and the surrounding vacuum jacket is critical. Existing piping included failed or iced vacuum-jacketed sections and a non-vacuum-jacketed segment that needed to be replaced.

The route passed through congested overhead conditions where field dimensions, existing supports, penetrations, relief piping, and adjacent utilities governed the work. Prefabricated spool pieces had to fit the verified conditions while maintaining system slope, expansion flexibility, vacuum performance, and access to valves and monitoring points.

The installation also required a planned shutdown and warm-up period before demolition. Zero-energy conditions had to be verified before the existing cryogenic piping could be safely disconnected.

How We Worked

JBrennon began by coordinating field measurements and completing the required openings before fabrication. Those verified dimensions allowed the specialty piping team to develop spool drawings and fabricate components that matched the existing distribution system.

The completed assembly used a ½-inch Schedule 10 stainless-steel inner process line inside a 2-inch Schedule 5 stainless-steel outer vacuum jacket. Multilayer insulation filled the vacuum space to help limit heat transfer and protect cryogenic performance.

After the liquid-nitrogen system was shut down, locked out, and allowed to warm, the team verified zero energy and removed the designated failed sections. The installation incorporated rigid and flexible vacuum-jacketed spools, bayonet connections, gas traps, keep-cold and keep-full components, an isolation valve, vacuum-monitoring connections, relief piping, and coordinated hangers and supports.

JBrennon provided the general-construction support needed to integrate the specialty installation. This included core drilling, protection of adjacent conditions, controlled dust and debris management, penetration restoration, firestopping, patching, and cleanup.

Quality verification included pneumatic testing, helium-leak testing, four-day vacuum-retention checks, and documented vacuum readings after installation. Once the system was returned to service, the team completed insulation and sealant touch-ups, sealed the penetrations, and coordinated final system labeling.

The Outcome

JBrennon delivered a repaired and extended cryogenic distribution system with the compromised piping removed and replaced by continuous vacuum-jacketed stainless-steel construction. The completed work combined field-verified fabrication, specialty cryogenic components, documented testing, and finished building restoration.

Final adjustments addressed insulation, sealant, penetration protection, and labeling so the installed system was complete and integrated with the surrounding facility infrastructure.

• Removed failed and iced vacuum-jacketed piping sections.

• Replaced a non-vacuum-jacketed condition with stainless-steel vacuum-jacketed piping.

• Installed a ½-inch process line within a 2-inch vacuum jacket.

• Added rigid and flexible spools, bayonets, gas traps, valves, vacuum-monitoring connections, relief piping, and supports.

• Restored penetrations with coordinated sealing, firestopping, insulation, and finish repairs.

• Completed pneumatic, helium-leak, and vacuum-retention verification.