The Quality Cryogenics' bayonet is a mechanical connection between two sections of Vacuum Jacketed Pipe that eliminates the need for welding or vacuum work in the field. Our bayonet consists of a male and female nose piece, machined out of dissimilar metals,that connects to form a dual seal.The first seal is a mechanical, close tolerance, connection between a "invar 36" male nose and a 304SS female nose cone. The second seal is a silicone O-ring placed between the male and female bayonet flanges. These combine to make a reliable heavy-duty cryogenic seal between the two VJ pipe sections, and simultaneously preserves the low heat leak of the system.

1. Place pipe supports in place every 10 ft (3 m) and every change of direction.
2. Place pipe on supports before engaging the bayonets.
3. Check alignment and slope of piping. The slope should be up in the direction of flow and 1"(25mm) up for every 50 feet (15.2m) in length.
4. Inspect the male bayonet nose end. It must be clean and free of burrs or damage.
5. Wipe bayonet couplings and O-ring with a lint-free cloth.
6. Lightly coat the silicon O-ring with a thin film of the supplied lubricant, and place in the groove on the male bayonet.
7. Coat the machined nose of the male bayonet with a thin film of the supplied lubricant to prevent galling during installation.
8. Engage the male and female bayonets (do not twist) and tighten the V-band to a loose fit. If resistance is felt, re-check alignment and re-engage.
9. Continue installing adjacent sections until all are engaged and in place.
10. Fine tune support heights to provide a smooth sloping pipe back to the tank.
11. When all is in place, tighten V-bands to a snug fit.
12. Finally, visually inspect entire system looking for stress risers and sufficient pipe supports.
13. Bayonets that are cold (have been in service) must be warmed to close to room temperature before disengaging. To do this, the VJ pipe must be drained and allowed to warm up approximately 24 hours before attempting disengagement.