Skip to Content

LSJ High Pressure Submarines

The LSJ (Longitudinal Sealing Joint) is used to run an electrical cable through a tank/pipe between two pressure-tight sections and to form a pressure-tight unit with the tank/pipe (RGPH seal) against incoming overpressure media through the cable if it has been damaged or cut in the pressure-tight sections.
The test pressure is 90 bar.

90 Bar
90 Bar

  • Custom designed
  • Pressure tested up to 90 bar
  • Tested and inspected acc. to specification
  • EMP-version available

The LSJ longitudinal cable joint is used as protection against incoming overpressure media/water through the pressure hull, vessels or barriers via the cables which have been damaged or cut. Application dimensions and cable types for the LSJ are decided by the customer. Generally the LSJ provides the same requirements as the cable. LSJ penetration are currently used in both submarines and oil platforms. Metal parts can be supplied in different materials according to customers requirement.

Two types of LSJ are available:
LVT Longitudinal sealed (The basic type of LSJ).
When a cable on the high pressure side (HP) is cut off, LSJ stops incoming water and protects the low pressure side (LP) from over pressure and water.

LVTT Longitudinal and cross sealed
If one or more of the cables on the HP side are damaged or cut off, these cables will be blocked, while the un-damaged cables are still intact.

Both types (LVT and LVTT) can be supplied with builtin protection against EMP (electromagnetic pulse due to lighting and nuclear blast).



Typical technical data (acc. to customer demands)

Hydrostatic pressure: Test pressure: 9 MPa (90bar) or acc. to specification.
Shock: Mechanical: 2000 g acc. to IEC 60068-2-27
Work temp. range: Min. -40°C , Max. +70°C
EMP: Peak 1 kA, raise and fall time 30 ns
Longitudinal seal: Min. 10-6 cc/s air with 1 bar diff


Following testing and inspections are available upon request
• Dimension and visual inspection
• Radiographic examination of moulding
• Leak detection test
• Hydrostatic pressure test
• High voltage test
• Insulation resistance test
• Conductor continuity and function test
• Result verification and inspection report/certificate
• Or other tests specified by the customer