HYDAC International SB330 Instrucciones De Servicio página 32

4. Commissioning
NOTICE
Bladder accumulators must be charged with
nitrogen. Check before commissioning (see
section 5.3).
The hydraulic accumulator must be checked
for corrosion.
Before commissioning and after charging the
hydraulic accumulator to the required pre-
charge pressure, check that the connections
on the fluid and gas sides are tightened
to the correct torque, and tighten further
if necessary. It must be ensured that no
attachment parts become twisted.
For tightening torques, see fold-out page.
The closing elements (e.g. protective plugs) on
the fluid side must be removed. The min./max.
operating data is permanently marked on the
hydraulic accumulator. The marking must be
kept in a legible condition.
EN
If venting is required, this must be done on
the oil-side connection prior to commissioning
the bladder accumulator, by opening the vent
screw (item 19) located on the oil valve.
4.1 Pre-charge pressure
Hydraulic accumulators are normally supplied
with a storage pressure (less than 2 bar).
If required, the hydraulic accumulator can
be supplied pre-charged to the customer's
required pressure setting. The pre-charge
pressure (p ) is indicated on a label on the
0
hydraulic accumulator shell, or stamped on the
hydraulic accumulator shell or engraved on the
name plate.
The hydraulic accumulator must be charged
by the operator to the required pre-charge
pressure (p ) before commissioning. The level
0
of the pre-charge pressure is calculated from
the operating data of the system.
Critical values of the pre-charge pressure
p ≤ 0.9 • p (p
0 1
Permitted pressure ratio: p
32
= minimum operating pressure)
1
: p ≤ 4 : 1
2 0
4.2 Charging gas
Hydraulic accumulators must only
be charged with nitrogen.
Never use other gases.
Risk of explosion!
In principle, only use nitrogen of at least
Class 4.0 (filtration <3 μm).
Deviations from these specifications must be
agreed with HYDAC.
4.3 Charging the hydraulic
accumulator
The HYDAC FPU charging and testing
unit must be used to charge the bladder
accumulator.
The max. operating pressures of the FPU must
be observed:
FPU-1: 350 bar
FPU-2: 800 bar
The charging and testing unit is supplied with
detailed operating instructions, see:
"Instruction manual for charging and testing
unit FPU"
No. 3.501.CE
During the charging process the hydraulic
accumulator must be securely mounted.
4.4 Permitted operating
temperatures
The permitted operating temperature is
determined by the material of the accumulator
shell, valve and bladder and is indicated on the
name plate and the certificate of conformity.
4.5 Permitted operating pressure
The permitted operating pressure is determined
by the material of the accumulator shell and
valve and is indicated on the name plate and
the certificate of conformity.
4.6 Hydraulic fluids
Hydraulic accumulators must only be operated
with pressure fluids with a minimum cleanliness
class of:
– NAS 1638 Class 6 or
– ISO 4406 Class 17/15/12