The Ultraflex hydraulic steering system for inboard engines is a basic kit for one steering station on vessels with a recommended hull length of 16/18 m. The system is dimensioned for a maximum rudder torque of 223 kgm and consists of a UP45-IR steering pump and a balanced UC442-I cylinder.
The UP45-IR is a hydraulic helm pump for mounting behind the dashboard. The pump features an axial piston system with seven pistons, 45 cm³ displacement per wheel revolution, and a 3/4" tapered stainless steel steering shaft. The integrated lock/check valve prevents rudder load from driving the pump in reverse, while the relief valve protects the system at up to 70 bar. The pump can be used with steering wheels up to 710 mm in diameter.
The balanced UC442-I cylinder provides the same number of wheel turns in both steering directions. The cylinder has a 300 mm stroke, 442 cm³ hydraulic volume, 50 mm internal cylinder diameter, and a 25 mm piston rod. The stated output force is 1,051 kg, and the maximum rudder torque is 223 kgm. The combination of 442 cm³ cylinder volume and 45 cm³ pump displacement corresponds to approximately 9.82 wheel turns from lock to lock.
The cylinder's documented dimension codes are A: 300 mm, B: 260 mm, C: 212 mm, D: 749 mm, E: 183 mm, F: 70 mm, and G: 110 mm. The mounting hole is Ø8.5 mm. The total depth of the pump is 160.5 mm, the front diameter is Ø115 mm, and the external protrusion is 15 mm. These measurements relate to the individual main components and should be included in the assessment of the installation space.
The installation must be supplemented with hydraulic oil and tubing according to the vessel's specific routing length. The cylinder can be connected using 12 mm copper tubing or Ultraflex TUR7 high-pressure hose. The pump has a straight 1/4" NPT fitting for 12 mm tubing. Hydraulic oil ISO VG22, item no. 45.027.01, can be used, while remote filler and service kit 45.270.07 can facilitate filling and bleeding.
The steering pump has component item no. 45.280.06 and manufacturer no. 41279H. The cylinder has component item no. 45.284.08 and manufacturer no. 42563K. The dimensioning must be verified against the vessel's steering geometry, installation space, and required rudder torque before assembly.
Key featuresHydraulic steering for inboard engines
Designed for one steering station
Recommended for 16/18 m hulls
Max. rudder torque: 223 kgm
UP45-IR pump with 45 cm³ per revolution
Balanced UC442-I cylinder with 300 mm stroke
Integrated check valve and relief valve
Max. system pressure: 70 bar
For 12 mm copper tubing or TUR7 high-pressure hose
Hydraulic oil and tubing or hoses are added separately
