Fuji Electric FSJ Instruction Manual page 121

Problem of fluid/piping
Steam temperature out of the specification range
Specification range: +120 to 180°C (50 A), +134 to 180°C
(65, 80, 100 A)
Steam pressure out of the specification range
Specification range: +0.1 to 0.9 MPa (G) (50 A), +0.2 to
0.9 MPa (G) (65, 80, 100 A)
Rapid pressure change (0.1 MPa or above in 10 seconds)
Wall thickness not between 2.8 to 4.5 mm
For SUS pipes and STPG pipes, the thickness may be
out of the specification scope depending on the schedule
(see "7.4 Piping data").
Flow velocity out of the specification range
Specification range: 0 to ±50 m/s (50, 65, 80 A ), 0 to ±30
m/s (100 A)
Accumulation of drainage
When the drainage level in the piping is higher than the
sensor mounting position, the sensor does not work.
Mixing of steam splashes
Dew condensation inside piping
Piping material besides SGP, SUS, or STPG
Uneven piping inner/outer surface due to rust, foreign
substances, or accumulated substances
Lining piping
Flowmeter failure
Converter circuit failure or detector failure
Cause
Cause
Install the device again to a place where the temperature
specification is satisfied.
Install the device again to a place where the pressure
specification is satisfied.
Install the device again to a place where there is no rapid
pressure change.
Install the device again to a place where the wall
thickness specification is satisfied.
Install the device again to a place where the flow velocity
specification is satisfied.
Discharge the drainage, or mount the detector to a place
where there is no drainage accumulation.
- Install the device again to a place where there are no
splashes.
- Cover the upstream piping of the detector and the
detector with a thermal insulating material.
- Install a steam trap or a separator on the upper side of
the detector.
Cover the piping and the detector with a thermal
insulating material.
Use SGP, SUS, or STPG pipes.
Polish the uneven outer surface of the piping ("5.3
Treatment of detector mounting surface") with a
sandpaper.
If the piping inner surface has a possibility of rust, install
the device again to a place without a possibility of rust.
Install the device again to piping that is not the lining
piping.
See "6.3.8 Remedying a hardware fault".
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Remedy
Remedy