<5. Maintenance>
5-8
IM 02C01B04-01EN
5.9.8 To Remove Force Bar
1. Remove force balance unit (Refer to section
5.9.5).
2. Using a 9/64" hex-key wrench, remove the two
force bar screws
3
. Force bar
4
can now be
removed through bottom. This unit should not
be further disassembled; if its diaphragm seal
is removed from force bar, leaks are likely to
occur after reassembly. If either force bar or its
seal requires replacing, they both should be
replaced as a unit.
3. Reverse this procedure to reassemble. Replace
O-ring at force bar seal. Before inserting force
bar into top-works, lubricate O-ring and top
of force bar with Vaseline or similar lubricant.
Carefully ease force bar into O-ring recess to
avoid damaging O-ring.
4. When reassembled, loosen the four cap screws
8
and
12
and two force bar screws
3
. Apply 10
kgf/cm
2
or bar, 1 MPa, or 150 psi to transmitter.
Tap body lightly and tighten all screws.
5. Calibrate transmitter (Refer to section 5.1.2).
5.9.9
Flapper Alignment
The flapper is aligned at the factory; a realignment
is required only if the force balance unit has been
disassembled. This alignment procedure requires
a spacing tool (see illustration), a 1/8" open-end
wrench, and a small screwdriver. (The wrench and
screwdriver are included in tool kit Model 6925-
6000, obtainable from YOKOGAWA.)
Caution: Use care in turning thin flexure alignment screw to
prevent shearing.
F0523.ai
150 mm handle
45°
25 mm
5.31 ± 0.03 mm DIA.
All dimensions except
diameter are approx.
Locknut
F0524.ai
Alignment
screw
1. If transmitter has optional zero elevation or zero
suppression kit, remove this assembly.
2. Connect an air supply regulated at a fixed
pressure 1.4 kgf/cm
2
or bar, 140 kPa, or 20 psi
to input, and a 0-1.5 kgf/cm
2
or bar, 0-150 kPa,
or 0-22 psi test gauge or manometer to output.
3. Loosen flexure locknut at bottom of force bar
(Refer to section 5.1.4).
4. Turn range wheel to top of range bar.
5. Using spacing tool as feeler gauge, insert tool
at lower end of range bar between threaded
surface and machined casting surface. Adjust
zero screw to get correct spacing for tool.
6. Loosen flapper alignment screw locknut and
adjust screw so that output is 0.2 kgf/cm
2
or bar,
20 kPa, or 3 psi.
7. Repeat Step 5. If output is not between 0.23
and 0.33 kgf/cm
2
or bar, 23 and 33 kPa, or 3.4
and 4.8 psi, repeat Steps 5 and 6 until output is
within these limits.
8. Retighten flapper alignment screw locknut.
Reinstall optional elevation or suppression
attachment. Tighten flexure locknut and check
calibration.
