Product Description; Hydraulic Steering System Operation; Warnings For The Correct Product Use - Ultraflex UC 378 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, 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 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 may be balanced or unbalanced. In
the unbalanced cylinders the two chambers have different volumes
and so they need a different number of turns of the steering wheel and
a different rotation effort. The balanced cylinders have same number of
steering wheel turns in order to move the helm from the center to the
end stroke in the two opposite 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 4,2 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 also not recommended, as the
response of the boat to steer is slowly.
1.2 Warnings for the product correct use
DANGER
Do not modify the steering cylinder in any way to fit it to your application, otherwise the cylinder 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
The UC 378 cylinder must not be installed on race boats.
WARNING
In dual helm applications horsepower must not exceed 450hp and boat speed must not exceed 55 m.p.h.
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HYDRAULIC CYLINDER FOR INBOARD ENGINE
of oil moved each steering wheel turn) and for
3
[1,7cu.in.] and the cylinder has a volume of 120 cm
3
Installation and Maintenance Manual
pump
l
l
l
hydraulic hose
l
cylinder
helm
[7,3cu.in.], the
3