Hydac FPK, FPS Operating Manual

Accumulators

Charging & Gauging Units

FPK / FPS Operating Manual

1.877.GO.HYDAC www.HYDACusa.com 1.888.99.HYDAC www.HYDAC.ca

PN#02068202 • ACU1403-1605 / 03.14

2

Charging & Gauging Units

PN#02068202 • ACU1403-1605 / 03.14

ACCUMULATORS

FPS

Version 4

FPK

Version 1

valve
protection
cap

(where applicable)

Valve
seal cap

O-ring

Allen Wrench 6 mm

(to be used to crack open M8 SHCS.
T handle on FPK Charging is not robust

enough to overcome recommended torque)

Valve protection cap

(where applicable)

O-ring (where applicable)

Socket Head
Cap Screw (M8)

Seal ring

T-Handle T-Handle

Check

Valve

Cap Nut Cap Nut

Manual

Bleed

Valve

Manual

Bleed

Valve

Figure 1

Figure 2

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ACCUMULATORS

General Warning!

Hydraulic accumulators are pressurized
vessels and only qualified technicians
should perform maintenance. For additional
information refer to HYDAC Operating
and Installation Instructions and HYDAC
Maintenance Instructions. Read all
instructions thoroughly before before
beginning any type of service or repair.

Tools Required

1. Gas Valve Core Tool.

2. Torque Wrenches.

3. Wrench(es).

Intervals Between Checking
Gas Precharge Pressure

The proper gas precharge pressure should
be set after each new installation or repair
by following the instructions under the
Operating and Installation Instructions
below. It should be rechecked at least once
during the first week of operation. If there
is no loss of gas precharge pressure, it
should be rechecked again in 3 to 4 months.
Thereafter, it should be checked at least
once a year. Recharge accumulator when
necessary.

Temperature Effect

To ensure that the recommended gas
precharge pressure is maintained,
even at relatively low of high operating
temperatures, the gas precharge pressure
should be adjusted for temperature. The
formula below relates the precharge
temperature (T0) to the operating
temperature (T).

Fahrenheit

P

0,T 0

= P

0,T 2

x (T0 + 460) / (T2 + 460)

Celsius

P

0,T 0

= P

0,T 2

x (T0 + 273) / (T2 + 273)

T0 = precharge temperature

T2 = maximum operating temperature

P

0,T 0

= gas precharge pressure at

precharge temperature

P

0,T 2

= gas precharge pressure at

maximum operating temperature

Operating and
Installation Instruction

Preparation

To check the gas precharge pressure in
an accumulator, it must first be isolated
from the system shut off, and all hydraulic
pressure relieved.

HYDAC gas valve version 4 (see fig. 2)

Unscrew the valve protection cap (where

applicable) and the valve seal cap.

HYDAC gas valve version 1 (see fig. 2)

Unscrew the valve protection cap (where

applicable). Slightly loosen the socket head

cap screw with a 6 mm Allen wrench (approx.

1/6 turn, see fig. 2).

NOTE: In order to connect the charging

hose to the FPK/FPS charging unit body,
the small ferrule must first be removed.

FPS Unit

Prior to connecting the charging and
gauging unit to an accumulator, turn
T-handle counter-clockwise until resistance
is felt. Close manual bleed valve by
hand tightening. Connect the unit to the
accumulator by screwing cap nut onto
HYDAC gas valve version4; hand tighten

(see fig. 1).

FPK Unit

Prior to connecting the charging and
gauging unit to an accumulator, close
manual bleed valve by hand tightening.
Connect the unit to the accumulator by
screwing cap nut onto HYDAC gas valve
version 1; hand tighten

(see fig. 1).

FPK Unit (with adapter FPK/SB)

Prior to connecting the charging and
gauging unit to an accumulator, take
adapter FPK/SB and unscrew the socket
head cap screw 3 full turns counter
clockwise using the 6 mm Allen wrench.
This is done to prevent gas valve damage
and leakage upon installation. Screw the
adapter FPK/SB onto HYDAC gas valve
version 4, hand tighten. Close manual bleed
valve on the FPK unit hand tight. Connect
FPK unit to adapter FPK/SB by screwing
cap nut onto the adapter; hand tighten.

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Charging & Gauging Units

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ACCUMULATORS

Checking Gas
Precharge Pressure

Connect the appropriate charging and
gauging unit to the accumulator following
the instructions under “Preparation” (see

page 2). Note: Temperature affects the

gas precharge pressure, please refer to
“Temperature Effect” (see page 2).

FPS Unit

Turn T-handle “A” clockwise a maximum of
3 full turns from the full counterclockwise
position. The gauge needle should indicate
the existing gas precharge pressure. If there
is no gas precharge pressure indicated
or if it is too low or too high, please follow
instructions under the appropriate section,
either “Pressure Release” (see below)
or “Charging” (to right). If desired gas
precharge pressure registers, please follow
the instructions under “Removal of Charging
and Gauging Unit” (see page 5).

FPK Unit

Turn T-handle counter clockwise a
maximum of 3 full turns. The gauge needle
should indicate the existing gas precharge
pressure. If there is no gas precharge
pressure indicated or if it is too low or
too high, please follow instructions under
the appropriate section, either “Pressure
Release” (see page 3) or “Charging” (see

page 3 ). If desired gas precharge pressure

registers, please follow the instructions
under “Removal of Charging and Gauging
Unit” ( see page 4).

Pressure Release

With the appropriate charging and gauging
unit attached as previously described,
gas precharge pressure can be released
by carefully opening manual bleed valve.
Release the gas precharge pressure very
slowly until the desired gas precharge
pressure is reached (this insures that the
gas temperature does not fluctuate greatly,
providing and accurate gas precharge
pressure). Close the manual bleed valve.
Allow the gas precharge pressure to
stabilize. (5 to 10 minutes) recheck, adjust if
required. Once the desired gas precharge
pressure is reached, please follow the
instructions under “Removal of Charging
and Gauging Unit” (see page 5).

Charging

Warning!

Never use oxygen or air - this could
cause an explosion! Use dry nitrogen or
other recommended gases.

HYDAC recommends the use of a pressure
regulator on the commercially available
nitrogen bottle to regulate pressure to the
charging and gauging unit.

Note: Full nitrogen pressure may damage
the gauge. Connect the charging hose to
a commercially available nitrogen bottle
by means of the G4 adapter (other adapters

are available, check with factory for type); the

adapter connects to the cap screw “G1”.
Connect cap nut of the charging hose to
check valve of the charging and gauging
unit (see fig. 1). Connect the appropriate
charging and gauging unit to the
accumulator by following the instructions
previously described (see page 2).

Initial Charging

When charging an accumulator that has no
initial gas precharge, allow 20 to 30 minutes
for the gas temperature and thus pressure
to stabilize. Recheck the gas precharge
pressure and adjust if necessary.

FPS Unit

Turn T-handle clockwise 3 full turns.
Proceed to “Filling”.

FPK Unit

Turn T-handle counter clockwise 3 full turns.
Proceed to “Filling”.

FPK Unit (with adapter FPK/SB)

Turn T-handle clockwise 3 full turns.
Proceed to “Filling”.

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Charging & Gauging Units

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ACCUMULATORS

Pressure Increase

When charging an accumulator that has
an existing gas precharge, allow 5 to 10
minutes for the gas temperature and thus
pressure to stabilize.

FPS Unit

Turn T-handle clockwise until the gauge
needle begins to deflect, then turn it another
full turn. Proceed to “Filling”.

FPK Unit

Turn T-handle counter clockwise until the
gauge needle begins to deflect, then turn it
another full turn. Proceed to “Filling”.

FPK Unit (with adapter FPK/SB)

Turn T-handle clockwise until the gauge
needle begins to deflect, then turn it another
full turn. Proceed to “Filling”.

Filling

Open the shut-off valve on the commercially
available nitrogen bottle and slowly fill the
accumulator with dry nitrogen gas.

Precharge very slowly until the pressure
in the accumulator reaches 100 psi. Once
100 psi is reached, the charging rate can
increase. Charging too quickly may damage
the accumulator.

Note: The gauge registers the line pressure,
not necessarily the accumulator pressure
while charging.

After allowing the appropriate time for
the gas temperature and thus pressure to
stabilize, adjust the gas precharge pressure
as required, refer to “Pressure Increase” (see

page 4) or “Pressure Release” (see page 3 ).

Once the desired gas precharge pressure
is reached close the shutoff valve on the
commercially available nitrogen bottle.
Remove the charging and gauging unit from
the gas valve as described under “Removal
of Charging and Gauging Unit” (see page 5).

Removal of Charging and
Gauging Unit

Close the shut-off valve on the commercially
available nitrogen bottle before removing
the charging and gauging unit.

FPS Unit

Turn T-handle counter clockwise until
resistance is felt to close the gas valve.
Open manual bleed valve to relieve pressure
in the charging and gauging unit. Proceed to
“Disconnecting”.

FPK Unit

Turn T-handle clockwise until resistance
is felt to close the socket head cap screw,
hand tighten. Open manual bleed valve to
relieve pressure in the charging and gauging
unit. Proceed to “Disconnecting”.

FPK Unit (with adapter FPK/SB)

Turn T-handle counter clockwise until
resistance is felt to close the gas valve.
Open manual bleed valve to relieve pressure
in the charging and gauging unit. Proceed to
“Disconnecting”.

Disconnection

Unscrew the charging and gauging unit
from the gas valve. Note: For FPK unit with
adapter FPK/SB it may be necessary to
loosen the connection between cap nut
and the adapter to remove the charging
and gauging unit. Check for leaks. None are
permissible.

Completion

HYDAC gas valve version 1 (see fig. 1)

Tighten socket head screw cap to 20 Nm
(15 lb-ft), and screw on valve protection cap

(where applicable); hand tighten.

HYDAC gas valve version 4 (see fig. 1)

Screw on valve seal cap torquing to 30 Nm
(22 lb-ft), and valve protection cap (where

applicable); hand tighten.

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Charging & Gauging Units

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ACCUMULATORS

Spare Parts

Item Description Part No.

9 O-Ring 006 01032
10 Seal-Ring 00601228
11 Gauge (select pressure range below)

10 (0 to 145 psi) 00606759

25 (0 to 350 psi) 00606760
100 (0 to 1400 psi) 00606761
250 (0 to 3500 psi) 00606762
400 (0 to 5800 psi) 00606763

12 Check Valve 00610004
13 Manual Bleed Valve 00236445

23

O-Ring - FPS 00626488
O-Ring - FPK 00601049

- 2.5m Hose 00236514

- 4m Hose 00236515

- 10m Hose 00373405

- ADAPTER G4 02068737

- ADAPTER A3 (FPK/SB) 00291533

- O-Ring - ADAPTER A3 (FPK/SB) 00601964

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Charging & Gauging Units

PN#02068202 • ACU1403-1605 / 03.14

ACCUMULATORS

M28x1.5

7/8-14UNF

A10

PN 02128849

M28x1.5

M16x2

A11

PN 03018210

M28x1.5

M16x2

(Test Point)

A12

PN 03930191

M28x1.5

Vg8

A9

PN 02128638

M28x1.5

7/8-14UNF

A

3 (ADAPTER FPK/SB)

PN 00291533

M28x1.5

M16x1.5

A

1

PN 00361619

M28x1.5

5/8-18UNF

A

2

PN 00361605

M28x1.5

7/8-14UNF

A

4

PN 00291536

M28x1.5

G1/4

A7

PN 02110629

M28x1.5

G3/4

A8

PN 02124524

M28x1.5

G3/4A

A6

PN 02108819

M28x1.5

M8x1

A5

PN 00291531

A Adapters (Gauge to Accumulator)

1.877.GO.HYDAC www.HYDACusa.com 1.888.99.HYDAC www.HYDAC.ca

© Copyright 2014 HYDAC CORPORATION • FPK/FPS Operating Manual PN#02068202 • ACU1403-1605

PN#02068202 • ACU1403-1605 / 03.14

W24.32x1/14"

M14x1.5

G1

SW32

M

Germany
Poland
Others

SW 32

SW 32

G2

PN 00236376

81

W24.32x1/14"

G5/8 - ISO 228

seal ring A6x10

Australia
Argentina
Great Britain
Vietnam
Others

52

G7

PN 00236377

W24.32x1/14"

W23x1/14"

SW 32

Korea

W24.32x1/14"

W21.8x1/14"

SW 32

37

G3

PN 02103421

Egypt
Lebanon
Israel
Others

W24.32x1/14"

SW 32

40

G8

PN 02103425

G1/2 - ISO 228

Brazil
Chile
Columbia
Others

SW 32

SW 32

G4

PN 02068737

81

W24.32x1/14"

W24.5x1/14"

seal ring A6x10

USA
Canada
Puerto Rico

SW 30

SW 32

G9

PN 00241168

58

W24.32x1/14"

M22x1.5

seal ring A6x10

Taiwan

SW 32

SW 32

G5

PN 00236373

79

W24.32x1/14"

W21.8x1/14"

seal ring A6x10

Italy

W24.32x1/14"

SW 36

45

G10

PN 02103427

ISO 228-G 3/4"

Russia
Trinidad
Tobago
Venezeula

seal ring A6x10

W24.32x1/14"

68

G6

PN 02103423

W22x1/14"

SW 32SW 32

Japan

SW 32

SW 32

G11

PN 03018678

64

W24.32x1/14"

G5/8-ISO228

seal ring A6x10

China

G Adapters (Charging to Accumulator)

Charging Hoses