HYDAC International FPU Notice D'utilisation page 20

1. Connect the pressure reducing valve to
the nitrogen bottle. Depending on the
particular country of manufacture for the
nitrogen bottle, the corresponding adapter
G G adapters [IV-1] must be used.
2. Close the pressure reducing valve.
3. Connect the charging hose to the pressure
reducing valve with the cap nut G [IV-2]
(G1, GM1, GW1) on the charging hose.
4. Connect the cap nut M [IV-2] of the
charging hose to the check valve C
[II-1] of the FPU.
5. Open the shut-off valve on the nitrogen
bottle. The pressure gauge at the pressure
reducing valve shows the starting pressure
(starting pressure = nitrogen bottle
pressure).
EN
6. SLOWLY SET the back pressure at the
pressure reducing valve.
The pressure gauge at the FPU also indi-
cates the back pressure (back pressure =
desired pre-charge pressure). We
recommend selecting a 10% higher accu-
mulator pre-charge pressure in order to
compensate for the influence in temper-
ature. This does not apply to SM.
7. The hydraulic accumulator is charged to
the selected pre-charge pressure.
8. After temperature compensation has taken
place, re-check the pre-charge pressure
and adjust if necessary.
6.4 Pressure reduction
(discharge)
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1. Slowly open release valve B [II-1]. The
nitrogen is released into the atmosphere (via
a draining hose in the case of custom-built
units).
6.5 To finish
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1. SB: Rotate the spindle A [II-1] counter-
clockwise to close the gas valve insert E
[III-3] in the hydraulic accumulator.
SK, SBO, SM: Rotate the spindle A
[II-1] clockwise to close the allen screw
P [III-4] in the hydraulic accumulator.
2. Close the nitrogen bottle.
3. Reduce pressure in the pressure reducing
valve, charging hose and FPU via the
release valve B [II-1] of the FPU.
4. Remove the charging hose from the FPU.
5. Loosen the cap nut D [II-1] and remove
the FPU from the hydraulic accumulator.
6. SB: Unscrew adapter A3 [III-1] and
insert the O-ring O [III-3] again. Check
the tightness of the gas valve using leak
detection spray. Screw and firmly tighten
the seal cap H [III-3] onto the accumu-
lator gas valve – tightening torque: 30 Nm.
Screw on cap nut S [III-3] by hand.
SK, SBO, SM: Tighten screw plug P
[III-4] with an allen key (AF width 6, DIN
ISO 2936) WZ2 [III-4] – tightening
torque: 20 Nm.
Check screw plug P [III-4] for leak-
tightness using leak detection spray.
Screw and tighten the seal cap S [III-4]
onto the screw plug P [III-4] – tightening
torque: 20 Nm.
7. Working with the FPU-2
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The following work relates to checking and
setting the pre-charge pressure in the
hydraulic accumulator.
7.1 Preparation
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Adapter A3H [III-2] must only be used with
the FPU‑2.
1. Check FPU for damage. A damaged FPU
must never be put into operation.
2. SB: Unscrew protective cap S [III-3] and
seal cap H [III-3] and remove O-ring O
[III-3]. Slightly unscrew the adjusting screw
of adapter A3H [III-2] and screw adapter
A3H [III-2] onto the accumulator gas valve.
SK, SBO, SM: Loosen the allen screw P
[III-4] with the spindle A [II-2].
3. Manually screw cap nut D [II-2] of the
FPU.
SB: onto the adapter A3H [III-2]
SK, SBO, SM: onto the accumulator gas
valve
4. Rotate FPU so that the pressure gauge is in
a good position for taking readings.
7.2 Testing
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1. Connect the charging hose to the pressure
boost system and FPU by means of the high-
pressure connection 9/16-18UNF C [II-2].
2. Close the release valve B [II-2] on the
FPU.
3. SB: Rotate the spindle A [II-2] clockwise to
open the gas valve insert E [III-3] in the
hydraulic accumulator until the indicator on
the pressure gauges moves.
SK, SBO, SM: Rotate the spindle A
[II-2] counterclockwise to open the
20 / 88
INT 3.501.BA15/03.24