Vetus HL12500A Instructions D'installation Et D'utilisation page 11

4.3 Oil Expansion Tank (optional)
A part of the EHP serves as an oil expansion tank. The expan-
sion volume required depends on the amount of oil in the con-
trol system and the expected minimum and maximum ambient
temperatures.
If the expansion volume is too small, oil will escape from the
EHP filler cap.
Model '125 kgf':
Install an extra oil expansion tank when:
- The total length of pipe exceeds 4
metres.
- Extreme temperature changes are
expected during operation.
- It is also recommended that an
extra oil expansion tank is fitted
when the vessel undergoes
extreme movement during opera-
tion.
- Two or more cylinders are fitted.
Model '320 kgf':
Always install an extra oil expansion tank.
Furthermore, an extra oil expansion tank simplifies filling the
system.
Fit the oil expansion tank above the EHP .
The Vetus oil expansion tank filler cap has an air hole; when fit-
ting an extra oil expansion tank, ensure an air hole is also pres-
ent.
4.4 Fittings
Never use Teflon tape for sealing the screw-thread connections.
A liquid sealant should be applied with great care; sealant in the
hydraulic system will cause problems.
4.4.1 Cylinder
The pipe connections are already fitted. A liquid sealant is used.
When the connections are refitted, remove the old sealant and
apply new liquid sealant.
4.4.2 EHP
Attach the two connective couplings to the two nylon pipes
which have already been fitted to the EHP .
Ensure the coupling with built-in throttle is correctly positioned.
A B
Electro-hydraulic lifting system
A B
EHP
4.5 Installing the Tubes
The separate parts of the hydraulic steering system are con-
nected together with nylon tube (4 mm internal, 6 mm outside
diameter).
To reduce internal resistance always keep the connecting hoses
as short as possible.
With reference to bleeding the system, it is recommended that
the horizontal hose sections should be fitted with a slope of
3 cm per metre (3/8" per ft); the pump side higher than the cylin-
der side.
Install the hoses in such a way that the risk of external damage
or attack by chemicals or high temperature is reduced to a min-
imum.
Protect hoses which pass through a bulkhead with grommets or
use bulkhead couplings.
Bends must be absolutely free of kinks; any kink in the system
restricts the free flow of the hydraulic oil.
With respect to the movement of wich the cylinder should be
allowed to the ends of both the tubes towards the cylinder, over
a length of 50 cms (20"), should be fitted with a large bend
radius.
After installation, blow through the hoses with nitrogen, or com-
pressed air, for example, (never use water!) to check for any
blockages and remove any pollutants.
The minimum bend radius for the nylon tube is 25 mm (1").
Always fit the hose with brackets; distance between brackets
about 50 cms (20").
The hose is shortened by
cutting.
Never cut the hose with a
saw (sawdust in the
hydraulic system will cre-
ate problems) or by clip-
ping (this deforms the
hose).
ENGLISH
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6.0901