- 14 -
DISMANTLING AND REASSEMBLY
WARNING - Process fluids and/or pressure
retained in the transmitter primary unit can cause
severe injury and death or damage to the
equipment. Plant Safety Procedures must be
followed when removing the instrument from
service or when draining or venting.
CAUTION - Dismantling and reassembly should
not be carried out on site because of the risk of
damage to components and printed circuits as a result
of adverse environmental conditions such as
humidity,dust,etc. The dismantling and reassembly
procedures given below should be carried out in the
listed order to avoid instrument damage.
Required tools
2 mm Allen key
3 mm Allen key
Small Phillips screwdriver
Small flat-bladed screwdriver
17 mm spanner (22 mm for mod. 622ED)
17 mm torque wrench (22 mm for mod. 622ED)
- (Range > 52 Nm - 39 foot lbs)
Dismantling
a) Screw down completely the cover locking screw, electronics
side, using the 3 mm Allen key
b) Unscrew and remove the covers
c) Unscrew the two fixing screws and remove the
secondary electronic assembly
d) Unplug the sensor cable
e) Remove the tang grub screw using the 2 mm Allen key
f)
Unscrew the housing taking care not to damage the
sensor cable or the connector
g) Loosen and remove the four flange fixing bolts using a
17 mm. spanner (22 mm for mod. 622ED).
Reassembly
Check that the "O" rings are not damaged : if in replace.
WARNING - Assembling flanges with incorrect
fixing bolts and nuts and improper "O rings" can
cause fracture or overstressing of bolts and release
of pressurized process material. Use only official
spare parts and do not exceed the specified torque
limits. DO NOT REMOVE the "O ring" fitted in the
sensor neck: it provides the housing a degree of
protection.
a) Refit the flange fixing bolts with a torque of 20 Nm (15 ft lbs)
using a 17 mm. torque wrench (52 Nm - 39 ft lbs for mod.
622, using a 22 mm torque wrench).
1 Nm is equivalent to 0.738 ft lbs (8.85 in lbs)
b) Insert the sensor cable in its recess at the bottom of the
housing.
c) Screw the housing down completely until the nesting of
housing/sensor assy is reached, then unscrew by one
complete turn maximum. Rotate the topwork in the
desired position and lock it with the tang grub screw
previously removed.
d) Plug the sensor cable to the secondary electronics. Fix
the electronic circuit by its screws.
e) Refit the covers and tighten securely.
WARNING - For Hazardous Location
installations, at least eight (8) threads on the
cover must be engaged in order to meet the
flameproof (explosion-proof) requirements.
f)
Unscrew the cover locking screw to secure the covers.
This is mandatory to meet "Flameproof requirements"
for Hazardous Areas installation.
Fig. 13 - Transmitter Sectional View
Secondary electronics
Electronics
screw
Blind cover
Flange bolts
Analog or digital
output indicator
or CoMeter
Extended
windowed cover
Blind cover
Windowed
cover
Microprocessor driven
integral display
Tang
screw
Terminal blocks
assembly
Sensor assembly
Calibration
screws
Nameplate
