HYDAC Permanent Gauging Blocks User Manual

Permanent Gauging Blocks

Installation Instructions

DESCRIPTION

The HYDAC Permanent Gauging
Block is designed to fit the
following types of HYDAC
accumulators: bladder, diaphragm
(with HYDAC gas valve version 4,)
and piston (with HYDAC gas valve
version 4.)

GENERAL

WARNING!

Before performing any maintenance
always relieve the gas and fluid
pressures completely from the
accumulator. Hydraulic
accumulators are pressurized
vessels and only qualified
technicians should perform repairs.
Never weld, braze or perform any
type of mechanical work on the
accumulator cylinder.

SPECIAL TOOLS REQUIRED

1) Charging and Gauging Unit

(1

2) Gas Valve Core Tool

3) 50 mm Open End Wrench (for

bottom repairable accumulator)

4) 32 mm Open End Wrench (for
top repairable accumulator)

5) Torque Wrench(es)

Currently the HYDAC Permanent
Gauging Block is only available for
use with HYDAC gas valve version 4.

Read all instructions thoroughly
before beginning any type of
service or repair work.

Refer to additional information
contained in the "Operating and
Installation Instructions for HYDAC
Accumulators."

1) for HYDAC gas valve version 4

use either the FPS Charging and
Gauging Unit or the FPK Charging
and Gauging Unit with adapter
FPK/SB.

!!

CAUTION

GAS CHARGING

PRESSURIZED VESSEL -

USE DRY NITROGEN GAS ONLY!

2

1.DISASSEMBLY

A) Relieve the fluid side pressure

completely from the accumulator.
Unscrew valve protection cap
(item 6 if applicable) and valve
seal cap (item 5).

For bottom repairable bladder
accumulators with 7/8"-14 UNF
gas valve proceed to step 1.B.

For top repairable bladder,
bottom repairable bladder with
M50x1.5 gas valve, diaphragm,
and piston type accumulators
proceed to step 1.C.

B) Insure there is a minimum of 150

PSI gas precharge pressure in
the accumulator by attaching the
proper HYDAC Charging and
Gauging Unit (refer to HYDAC
Charging and Gauging Unit
brochure #02071833). If the gas
precharge pressure is too low,
increase it to 150 PSI. Once the
gas precharge pressure is set
remove the Charging and
Gauging Unit from the gas valve.
Remove and discard lock nut
(item 4) and replace it with the
new low profile lock nut (item 4)
furnished with the permanent
gauging block. Torque the new
low profile lock nut. Proceed to
step 1.C.

C) Attach the proper HYDAC

Charging and Gauging Unit and
completely relieve the gas
precharge pressure. Refer to
HYDAC Charging and Gauging
brochure #02071833.

D) After the gas precharge pressure

is completely relieved, remove
the Charging and Gauging Unit
from the gas valve.

E) Remove and discard the gas

valve core (item 3) and o-ring
(item 7) from the gas valve. Be
sure to use a gas valve core tool
to remove the gas valve core.
The use of any other implement
may damage the internal threads
of the gas valve, thus the bladder
or complete accumulator may
have to be replaced.

2.ASSEMBLY

A) Before attaching the HYDAC

Permanent Gauging Block, be
certain the o-ring (11x 2) in the base
of the block is properly seated.

For diaphragm, piston, bottom
repairable bladder with M50 gas
valve, and top repairable bladder
accumulators proceed to step 2.B.

For bottom repairable bladder
accumulator with 7/8"-14 UNF
gas valve proceed to step 2.C.

B) For top repairable bladder

accumulators, first screw on the
modified valve protection cap
(item 6A). Screw the Permanent
Gauging Block onto the
accumulator gas valve (use a 32
mm Open End Wrench), and
torque to 50 Newton Meters (37
foot pounds). Proceed to step

2.D.

C) Screw the Permanent Gauging

Block onto the accumulator gas
valve, hand tighten only. Use a
50 mm open end wrench or
equivalent (for top repairable
accumulators use a 32 mm Open
End Wrench), turn the Permanent
Gauging Block just until it is
tight. DO NOT OVER TIGHTEN. If
the Permanent Gauging Block is
over tightened at this stage of
installation the bladder may twist
in the shell and fail.

Attach appropriate HYDAC
Charging and Gauging Unit (refer
to HYDAC Charging and Gauging
Brochure #02071833). Apply dry
nitrogen gas charge of 150 PSI
to the accumulator. This will
secure the bladder and prevent it
from twisting in the shell when
tightening the Permanent
Gauging Block. Remove the
HYDAC Charging and Gauging
Unit. Torque the Permanent
Gauging Block to 50 Newton
Meters (37 foot pounds).

D) Attach appropriate HYDAC

Charging and Gauging Unit (refer
to HYDAC Charging and Gauging
Unit Brochure #02071833) and
apply proper gas precharge
pressure. Remove HYDAC
Charging and Gauging Unit.

E) Screw on the valve seal cap

(item 5), torque to 30 Newton
Meters (22 foot pounds).

3