Product Description; Hydraulic Steering System Operation; Warnings For The Correct Product Use - Ultraflex UP 20 F Manuel D'installation Et D'entretien

ULTRAFLEX

1 PRODUCT DESCRIPTION

1.1 Hydraulic steering system operation

All ULTRAFLEX hydraulic steering systems are designed in conformity with UNI-EN-ISO 10592 and A.B.Y.C. P21
regulations. All ULTRAFLEX steering systems can operate at temperatures between -18°C (0°F) and +77°C
(+170°F). All the components are made for the marine environment, using materials and working processes
which offer long life and safety under the most extreme conditions. A hydraulic steering system consists of
a steering pump located on the dashboard, a cylinder tied to the
rudder or to the outboard or sterndrive engine and the connecting
hoses (see picture). Under normal operating conditions, a turn of
the steering wheel will pump the oil, which flows in through the
hoses to the cylinder, according to the turn direction. With the
consequent cylinder movement the oil will flow to the pump through
the hoses and at the same time moves the engine or the helm which
are connected to the cylinder. The pumps equipped with a nonreturn
valve, which prevents outgoing fluid from returning along the same
hose. allow the operation of the steering systems with two or more
steering stations. The cylinders are double-acting and they can be
balanced or unbalanced. In unbalanced cylinders the two chambers
have different volumes and therefore they require a different number
of steering wheel turns and a different steering wheel rotation effort
with the same movement in the two directions. The balanced cylinders
require the same number of turns of the steering wheel to move the helm from the centre to the end of
stroke in the two opposed directions.
A well balanced steering system needs a correct choice of the pump for the cylinder. ULTRAFLEX produces
different pump models, which have different capacity (cm
each type of installation. While choosing the pump it is important to consider the cylinder volume. The
number of starboard and port turns is determined by the ratio between the cylinder volume and the pump
capacity.
Example: if the pump has a capacity of 28 cm
formula looks like this: 120/28=4,2. Accordingly, the steering wheel will turn about 4 times before the cylinder
will completely turn from one side to the other. In case of installations with double cylinders connected in
parallel the cylinder volume must be added. Applications with less than 4 turns are not recommended, as
they need a higher effort, also applications with more than 8 turns are not recommended, as the response
of the boat to steer is slowly.

1.2 Warnings for the correct product use

DANGER
Do not modify the pump in any way to fit it to your application, otherwise the pump will no longer operate in
safety and it will endanger the boat and the occupants.
WARNING
All ULTRAFLEX steering systems must not be installed on boats equipped with engines whose maximum
horsepower is higher than the horsepower rating approved by boat manufacturer.
WARNING
ULTRAFLEX steering systems must not be installed on race boats.
of oil moved each steering wheel turn) and for
3
[1,7cu.in.] and the cylinder has a volume of 120 cm
3
PUMP FOR HYDRAULIC SYSTEMS
Installation and maintenance manual
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engine
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cylinder
hydraulic hoses
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