SIVL - Super Insulated Vacuum Line

Often referred to as Vacuum Insulated Piping or VJ piping, super insulated vacuum piping provides the most efficient method for transferring liquid cryogens from one place to another.

Used mainly for liquid nitrogen (LN2) , it can also be used for liquid argon (LAr). Variants can be made for liquid oxygen (LOX), liquid hydrogen (LH), liquid helium (LHe), liquid natural gas (LNG) and liquid carbon dioxide (LCO2).

SIVL comes in a range of standard diameters from ½” NB (18mm ID) to 3” NB (85mm ID) to suit your requirements and both smaller and larger bespoke sizes can also be manufactured. Lines can be site welded by experienced welders or by local partners, or they can be manufactured with bayonet couplings to be plugged together by local labour with no experience of cryogenic lines.

Lines offered are bespoke built with elbows and tees incorporated into sections to minimise the number of joints required on site and thus reduce the total heat inleak.

Lines can be altered or extended at a later date and when using our own teams, most other makes of lines can also be worked on and modified

SIVL is supplied via Wessington selected partners


Key Features

  • Outer line remains ambient when inner line is at cryogenic temperatures.
  • Polished stainless steel outer - suitable for any environment, even category 3 or 4 laboratories.
  • Pipework has an indefinite lifetime with only minimal maintenance required.
  • Pipework can be modified or extended at a later date to add in additional outlets.
  • Can be supplied in kit form for installation by local labour.
  • Small outer diameter in comparison to equivalent lagged lines.
  • Outer pipe remains a fixed length. All contraction is taken up on the inner line.


Technical Specification

½” NB: ID 18mm x OD 76mm

1” NB: ID 30mm x OD 89mm

1½” NB: ID 45mm x OD 102mm

2” NB: ID 57mm x OD 114mm

3” NB: ID 85mm x OD 168mm

Optional Extras

Cryostop Valve

Electro-pneumatically actuated shut off valve at supply tank

Vapour Vent units

Mechanical devices for keeping the line full of liquid at all times.