<8. Maintenance>
8-3
IM 01C25B01-01E
8.4 Disassembly and
Reassembly
This section describes procedures for disassembly
and reassembly for maintenance and component
replacement.
Always turn OFF power and shut off and release
pressures before disassembly. Use proper tools for
all operations. Table 8.2 shows the tools required.
Table 8.2
Tools for Disassembly and Reassembly
Tool
Quantity
Remarks
Phillips
screwdriver
1
JIS B4633, No. 2
Slotted
screwdriver
1
Allen wrenches
3
JIS B4648
One each, nominal 3, 4 and
2.5 mm Allen wrenches
Wrench
1
Width across flats, 17 mm
Torque wrench
1
Adjustable
wrench
1
Socket wrench
1
Width across flats, 16 mm
Socket driver
1
Width across flats, 5.5 mm
Tweezers
1
CAUTION
Precautions for ATEX Flameproof Type
Transmitters
• Flameproof type transmitters must be, as
a rule, removed to a non-hazardous area
for maintenance and be disassembled and
reassembled to the original state.
• On the flameproof type transmitters the two
covers are locked, each by an Allen head
bolt (shrouding bolt). When a shrouding bolt
is driven clockwise by an Allen wrench, it is
going in and cover lock is released, and then
the cover can be opened.
When a cover is closed it should be locked
by a shrouding bolt without fail. Tighten the
shrouding bolt to a torque of 0.7 N·m.
Shrouding Bolt
Shrouding Bolt
F0802.ai
Figure 8.2
Shrouding Bolts
8.4.1 Replacing the Integral Indicator
CAUTION
Cautions for Explosion-proof/Flameproof
Type Transmitters
Users are prohibited by law from modifying the
construction of a explosion-proof/flameproof type
transmitter. This would invalidate the agency
approval for the use of the transmitter in a rated
area.
It follows that the user is prohibited from using
a explosion-proof/flameproof type transmitter
with its integral indicator removed, or from
adding an integral indicator to a transmitter. If
such modification is absolutely required, contact
Yokogawa.
This subsection describes the procedure for
replacing an integral indicator. (See figure 8.3)