HYDAC International QHP Instrucciones De Servicio página 5

4.1 Pre-charging procedure
A
I
D
H
G
B
WARNING:
Only suitably trained and competent
personnel shall carry out any
pre-charging.
NEVER LEAVE PRE-CHARGING
EQUIPMENT UNATTENDED DURING USE.
The following procedure must be
followed to ensure safe pre-charging of
the accumulators. All pre-charging
equipment should be supplied by QHP –
see catalogue for details.
• Release pressure from the fluid side of
• the piston accumulator.
• Remove protective cap (5) and if fitted
• gas valve sealing cap on assembly (3)
• Attach nitrogen regulator (A) to
• nitrogen bottle (B)
• Ensure hand-wheel (E) on charging set
• (C) is fully retracted, including pin.
• Fit charging set assembly (C) to accumu
• lator gas valve (3)
• Connect charging hose (D) between
• nitrogen regulator (A) and charging set
• assembly (C)
• Check bleed (F) is fully closed.
Set nitrogen bottle gas regulator (A) to 25
psi.
E
C
F
3
NOTE
The Nitrogen Pressure Regulator Valve
shall have two gauges, one for the high
pressure (upstream) and one for the
reduced pressure (downstream). To avoid
overcharging due to incorrect setting, the
pressure-reducing device shall have a
maximum set pressure not exceeding the
maximum allowable pressure PS of the
accumulator.
To avoid overcharging by malfunction, the
pressure-reducing device shall be
equipped with a relief device limiting the
downstream pressure.
• Slowly turn hand-wheel (E) clockwise
• one to one and a half turns to depress
• the gas valve core.
• Open nitrogen cylinder valve (G) using
• bottle key (H), gas pressure will be
• indicated on the right hand gauge of the
• regulator.
• Turn regulator handle (I) clockwise until
• gas pressure register on the left hand
• gauge. This pressure should be 10%
• higher than the required pre-charge
• pressure.
• Allow the gas pre-charge pressure to
• stabilize, adjust if required.
• Check gas pre-charge pressure on
• charging set assembly (C). When this is
• equal to the pressure on the pressure
• regulator, close nitrogen bottle valve
• (G).
• If the pressure is too high, it can be
• reduced via the bleed (F)
• Turn handle (E) on charging set
• anticlockwise to seal gas valve (3).
• Open bleed valve (F) to vent gas from
• charging valve (3).
• Remove charging assembly (C) and
GB
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