Page 41 - ULTRAFLEX Katalog 2021

ULTRAFLEX HYDRAULIC STEERING SYSTEMS

All the components of Ultraflex hydraulic steering systems are made specifically for the marine environment, using materials
and working process which offer long life and safety for the most extreme conditions.

HOW THE SYSTEM WORKS
A hydraulic steering system consists of a steering pump, a cylinder tied to the rudder or to the outboard or sterndrive engine
and the connecting nylon or copper tubing.
Under normal operating conditions, a turn of the steering wheel will send the oil from the helm unit into one of the two
connecting hydraulic lines. 39
The oil will be pumped into one of the chambers of the cylinder and either extend or retract the cylinder rod, depending on
the steering wheel rotation.
The fluid going out from the other chamber of the cylinder is returned to the helm via the other hydraulic line.
There are two basic components in all the hydraulic steering systems: the helm unit and the cylinder, connected by nylon or
copper tubing.The helm unit consists of both a hydraulic pump and a valve assembly.
The valve assembly prevents outgoing fluid from returning along the same line, isolates each steering station, locks the
rudder and eliminates rudder “feedback” to the helm.
The cylinders are double acting and may be balanced or unbalanced (in which case the rod extends through only one end of
the cylinder).

SUGGESTIONS AND WARNINGS WHEN SELECTING A HYDRAULIC STEERING SYSTEM

The strength required to drive a boat equipped with a hydraulic steering system is inversely proportional to the number of turns
of the wheel lock-to-lock. The wheel turns are determinated by the ratio between the cylinder volume, pump displacement.
With the same type of cylinder installed on the engine, the less are the turns, the faster is the response but higher is the effort;
more wheel turns, slower is the response and lower is the effort.

Other factors that can influence steering effort are:
• Vessel speed
• Rudder dimension, or engine power
• Propeller selection
• Hull type (displacement, planing, etc.)
• Sea conditions
• Oil viscosity

CROSS REFERENCE

HELM PUMPS CYLINDRES

ULTRAFLEX ® SEASTAR ® ULTRAFLEX ® SEASTAR ®

UP18 BayStar™ HH4311 UC81-OBF - HYDRAULIC STEERING SYSTEMS - CROSS REFERENCE
UP20 F BayStar™ HH4314 UC95-OBF Baystar™ HC4645
UP20 T BayStar™ HH4315 UC128-OBF Seastar™ HC5345
UP25 F Seastar™ 1.4 HH5269 UC130-SVS Seastar™ HC6345
UP25NV F -
UP25 T Seastar™ 1.4 HH6544 UC68-OBS -
UP28 F Seastar™ 1.7 HH5271 UC132-OBS Seastar™ HC5370/5328
UP28 T Seastar™ 1.7 HH6541
UP 28 R Seastar™ 1.7 HH5261 UC69-I Baystar™ HC4461-3
UP33 F Seastar™ 2.0 HH5273 UC116-1 Seastar™ HC5312
The above Cross UP33NV F Seastar™ 2.0 HH5760 UC168-I Seastar™ HC5314
UC215-I
Reference chart UP33 T Seastar™ 2.0 HH6543 UC293-I Seastar™ HC5319
-
-
has been drawn to UP33 R Seastar™ 2.4 HH5272 UC378-I -
UP39 F
facilitate a functional UP39 T Seastar™ 2.4 HH6542
comparison among UP39 R Seastar™ 2.4 HH5262
brands and should UP45 F Seastar™ 3.0 HH5283
be used as general UP45 T -
reference only. UP45 R Seastar™ 3.0 HH5265
UP28 F-SVS Seastar™ PRO - HH5779
For any further UP28 T-SVS Seastar™ PRO – HH6573
information please UP33 F-SVS Seastar™ PRO - HH5770
contact our Technical UP33 T-SVS Seastar™ PRO – HH6574
Service UP39 F-SVS Seastar™ PRO - HH5772
UP39 T-SVS Seastar™ PRO - HH6188