IM 01C25R01-01E
9-6
9. MAINTENANCE
CAUTION
Cautions for Flameproof Type Transmitters
Users are prohibited by law from modifying the
construction of a flameproof type transmitter. If
you wish to replace the capsule assembly with
one of a different measurement range, contact
Yokogawa.
The user is permitted, however, to replace a
capsule assembly with another of the same
measurement range. When doing so, be sure to
observe the following.
• The replacement capsule assembly must have
the same part number as the one being re-
placed.
• The section connecting the transmitter and
capsule assembly is a critical element in
preservation of flameproof performance, and
must be checked to verify that it is free of
dents, scratches, and other defects.
• After completing maintenance, be sure to
securely tighten the setscrews that fasten the
transmitter section and pressure-detector
section together.
Removing the Capsule Assembly
IMPORTANT
Exercise care as follows when cleaning the
capsule assembly.
• Handle the capsule assembly with care, and be
especially careful not to damage or distort the
diaphragms that contact the process fluid.
• Do not use a chlorinated or acidic solution for
cleaning.
• Rinse thoroughly with clean water after clean-
ing.
1) Remove the CPU assembly as shown in subsection
9.4.2.
2) Remove the two setscrews that connect the
transmitter section and pressure-detector section.
3) Remove the hexagon-head screw and the stopper.
4) Separate the transmitter section and pressure-
detector section.
5) Remove the nuts from the four flange bolts.
6) While supporting the capsule assembly with one
hand, remove the cover flange.
7) Remove the capsule assembly.
8) Clean the capsule assembly or replace with a new
one.
Reassembling the Capsule Assembly
1) Insert the capsule assembly between the flange
bolts, paying close attention to the relative positions
of the H (high pressure side) and L (low pressure
side) marks on the capsule assembly.
Replace the two capsule gaskets with new gaskets.
2) Install the cover flange on the high pressure side,
and use a torque wrench to tighten the four nuts
uniformly to a torque shown below.
T0903E.EPS
Torque(N·m) {kgf·m}
Model
EJX910A
17 {1.7}
3) After the pressure-detector section has been reas-
sembled, a leak test must be performed to verify
that there are no pressure leaks.
4) Reattach the transmitter section to the pressure-
detector section.
Reattach the stopper with the hexagon-head screw.
5) Tighten the two setscrews. (Tighten the screws to a
torque of 1.5 N·m)
6) Install the CPU assembly according to subsection
9.4.2.
7) After completing reassembly, adjust the zero point
and recheck the parameters.
F0905E.EPS
Transmitter section
Pressure-detector section
Cover flange
Capsule gasket
Flange bolt
Setscrew
Nut
Figure 9.5
Removing and Mounting the Pressure-
detector Section
