Valmet TS, Инструкция по установке и эксплуатации, Страница: 37 / 63

11. Replacing components
11.1. Pressure test of sensor housing
NOTE: If the sensor is installed in ATEX Zone 2,
whenever the sensor housing has been opened (e.g.
when replacing components) it must be pressure tested
before use to ensure its suitability for ATEX Zone 2. If
the sensor is installed in a non-hazardous location,
pressure testing is not necessary.
Tools required:
– Pressure tester K12446
– Allen key 6mm
– Stop watch
The sensor assembly must be complete, with all
covers installed. During the test the sensor should be
under constant temperature conditions. See the
manual supplied with the pressure tester for more in-
formation.
NOTE: Temperature changes will affect test results!
Fig. 1. Pressure test port on sensor housing.
Test procedure:
1.
Disconnect Valmet TS power supply.
2. Open the Valmet TS test port plug (Fig. 1).
3. Switch on the pressure tester gauge, reset the
reading if needed. Check that the gauge shows
the unit
Pa ; if not, change the unit as instructed in
the pressure gauge manual.
4. Pull the syringe piston to the outer position.
5. Connect tester hose coupling to Valmet TS test
port.
6. Pressurize the electronics housing: push the syr-
inge piston in until the pressure gauge reading is
approximately
300 Pa .
7. Start the stop watch.
8. The device passes the test if
– pressure remains over 270 Pa for at least
14 seconds (less than 10% drop from initial
value), or
– pressure remains over 150 Pa for at least
90 seconds (less than 50% drop from initial
value).
9. If the device fails the test:
– Check the connection of pressure tester to test
port.
– If the connection is OK, locate the leak e.g. by in-
jecting soap liquid on the sealed connection points
of the sensor, and watch for bubbles while the
housing is being pressurized.
– After the necessary repairs, repeat the pressure
test.
10. Disconnect the pressure tester hose coupling from
the sensor, and close the test port again with a
plug.
11. Switch off the pressure tester gauge. Push the
syringe back to the inner position.
12. Before connecting the Valmet TS power supply,
inspect visually the sensor housing, seals, threads
and cable conduits. There must be no signs of
damage.
Installation & Owner's manual, OUL00489 V2.3 EN 37 Valmet Total Solids Transmitter