Air Piping; Valve Body Removal; Actuator Removal; Bonnet Disassembly - Fisher Baumann 84000 Instruction Manual

84000 Valve

Air Piping

1. For an air to extend actuator (air to close
action), connect the actuating air pressure line to the
1/4 NPT opening in the upper diaphragm case. For
an air to retract actuator (air to open action)
connect the actuating air pressure line to the 1/4
NPT in the lower diaphragm case.
2. Use 6.4 mm (1/4 inch) O.D. tubing or equivalent
for all air lines. If the air line exceeds 8 m (25 ft) in
length, 9.5 mm (3/8 inch) tubing is preferred. Air
lines must not leak. Air pressure should not exceed
2.5 bar (35 psig).

Valve Body Removal

Reference figures 4, 5, and 6.
(Not Required For Actuator Reversal)
For field replacement of the diaphragm (key 8),
follow steps 1 through 4 below.
Do not squeeze the valve body in a
vise.
1. For fail closed action (air to open), stroke the
actuator up to take pressure off from the diaphragm
pushing against seat. For fail open action
(air to close), there is no need to stroke actuator.
2. Remove the bonnet screws (key 18) for NPS 1
valves or the clamp (key 11) for NPS 1 1/2 or 2
valves.
3. Lift the bonnet assembly (key 2) with the actuator
from the valve body (key 1).
4. Once disassembled; for fail closed action ONLY,
release pressure from the actuator to be able to
unscrew the diaphragm, for fail open action you
must pressurize the actuator to unscrew the
diaphragm. This is the only action required for
inspection or cleaning.
5. Stroke the actuator down to exert some pressure
and remove the diaphragm (key 8) by unscrewing
the diaphragm (key 8) from the compressor (key 5).
Remove the bonnet O ring (key 15) (NPS 1 1/2 and
2 valves only). Wipe the diaphragm (key 8) with a
clean soft cloth and examine for wear.
6. Inspect the valve body sealing surfaces. If valve
leakage becomes excessive, replacement of the
diaphragm (key 8) may be necessary.
4
Note

Actuator Removal

To remove the actuator, unscrew the drive nut
(key 9) and loosen the jam nuts (key 27). Unscrew
the piston stem (key 3) from the actuator stem.
CAUTION
Avoid personal injury or property
damage from sudden release of
pressure or bursting of parts. Remove
the actuator before attempting to
disassemble the valve.

Bonnet Disassembly

Actuator Removed
Remove the diaphragm (key 8) and the bonnet
O ring (key 15) (NPS 1 1/2 and 2 valves only) per
instructions under the previous Valve Body Removal
section. Proceed as follows:
1. Turn over the bonnet assembly (key 2).
2. Pry out the retaining ring (key 7) using a small flat
screwdriver.
3. Remove the wave springs (key 6), compressor
(key 5) and drive mechanism (key 4).
4. Push out the piston stem assembly (key 3).
Clean and replace as required.
For NPS 1 1/2 & 2 valves, measure the
gap between the free ends of the
clamp (key 11) and return to this
position upon reassembly to minimize
change in zero calibration.

Bonnet Reassembly

Actuator Removed
For correct orientation of the sub assemblies to the
bonnet refer to figure 7, exploded view.
1. Insert the piston stem assembly (key 3) into the
bonnet (key 2).
2. Orient the drive mechanism as shown in figure 7.
3. Verify that the machined surfaces at the end of
the rectangular plates are in full contact with the
machined recess inside the bonnet (key 2).
Instruction Manual
June 2010
Note