Hydrostatic Release Units (HRU)

Hydrostatic Release Units (HRU)
Hydrostatic Release Units (HRUs) are a quick release system to allow your life raft to inflate automatically in an emergency situation without you having to do anything.

More details


Salcom Servo-Release™ HRU

Designed and fabricated from tough non-corrosive materials and with an integral quick release mechanism, the Salcom Servo-Release™ HRU represents innovative thinking and real cost saving benefits in automatic hydrostatic release units for life rafts. 

At a depth of 1.5 to 4 metres, water pressure alone is sufficient to depress an internal diaphragm in the HRU to operate the release mechanism. This offers considerable advantages both in reliability and performance as the releasing system does not depend on a sharp blade, a pyrotechnic device or a battery to release the life raft.


Salcom Servo-Release™ HRUs meet all international regulations and each unit is individually tested to ensure they are most reliable HRU in an emergency situation.


How Does it Work?

The Salcom Servo-Release™ Hydrostatic Release Unit can be fitted to any container packed

life raft from 4 – 150 person capacity, to allow unattended deployment in a sinking vessel. At a depth of between 1.5 to four metres, water pressure depresses an internal diaphragm within the device.

This operates the release mechanism that secures the raft container to its cradle or mounting position. The life raft will then float free of the sinking vessel and rise towards the surface with the raft’s painter line paying out as the vessel continues to sink. When all the free length of painter line is paid out, the inflation mechanism of the life raft is activated, the raft inflates and continues to rise towards the surface. At this point of inflation, the weak link on the HRU breaks and allows the life raft to continue to float to the surface ready for boarding.


Salcom Servo-Release™ HRU Features

Suitable for life rafts from 4 to 150 persons – maximum load 10kN (2250 lbs).

Fabricated from non-corrosive, quality components, including marine grade stainless-steel.

Highly reliable release mechanism – does not depend on sharp blade, pyrotechnic device or battery.

Includes manual release lever – no Senhouse slip-hook required.

Service life of two years – no maintenance required.

Complies with SOLAS and IMO regulations, Lloyds Register Certified, US Coast Guard approved.