Vacuum Jacketed pipe is essentially two pipes in one: an inner carrier pipe in which the cryogenic liquid is transferred, and an outer pipe that supports and seals the vacuum insulation, forming the "Vacuum Jacket". The inner line is suspended inside the outer jacket by a series of non-conductive supports. Depending on system design pressure, internal or external expansion joints are used to compensate for thermal contraction of the inner line.

The inner carrier pipe and the outer jacket are constructed from stainless steel pipe or tubing. The inner line is wrapped with a multi-layered super insulation which blocks radiative heat transfer. The entire annular space between the inner line and the outer jacket is evacuated to prevent conductive and convective heat transfer. The vacuum space is then factory sealed, forming a "static vacuum". Chemical getters are used to maintain the vacuum space and provide maintenance free operation for 20 plus years.

Due to shipping and handling constraints, VJ piping is built in individual "spool" sections and assembled in the field using either bayonet or field joint connections. Each spool section is evacuated using a combination pump-out / relief port. Optional vacuum gauge tubes (DV-6R) with isolation valves are available.