Hydraulic Double-Acting Actuator (Type HSTP - D)

BESI Marine Systems GmbH produces double-acting hydraulic actuators type HSTP-D.

These are high pressure actuators which benefit from the combination of high oil pressure levels of 100 up to 135 bar - on request up to 160 bar - and small overall dimensions as well as attractive torque rates.


The HSTP-D actuator may be installed in any place - submerged in medium, in dry spaces, on deck, or in hazardous areas. The actuator needs two hydraulic supply pipes For easy installation, we recommend endless pipes (8 x 0.5 stainless steel) from coil, preferably bundled pipes, comprising two or a multiple of two hydraulic lines.

Position response

The valve position is determined by limit switches mounted externally on the actuator, or by volume transmitters installed inside the central control unit, such as the solenoid valve cabinet. The BESI volume transmitters are accepted by all major classification societies and are type-approved by Germanischer Lloyd (GL). They provide an inexpensive but very precise and reliable signal transmission and eliminate the need for any electric cabling to the valves. This ensures economic installation even in hazardous areas of a ship.

Emergency Operation

The actuators are equipped with couplings for quick connection to a portable hand-pump for emergency operation. Actuators in medium have their control blocks for manual control installed outside the tanks, and are connected by hydraulic pipes.


Type Torque (Nm) Weight (kg)
open close
HSTP 51 - 40/40 280 280 10,0
HSTP 78 - 40/40 450 450 20,0
HSTP 78 - 60/60 1020 1020 25,0
HSTP 108 - 63/63 1590 1590 38,0
HSTP 108 - 90/90 3240 3240 41,0
HSTP 156 - 63/63 4600 4600 66,0
HST2P 156 - 80/80 7500 7500 79,0
HST2P 156 - 100/100 11780 11780 135,0
ISO 9001 certified

BESI Marine Systems GmbH
Vorweide 4
D-28259 Bremen