EXPO D760-ET MiniPurge, Руководство пользователя

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ML548 | v11
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• This test can be carried out several times to ensure repeatability and compliance.
Refer to the Maintenance of the System section if the Relief Valve needs recalibrating.
8. Reset CLAPS regulator & Purge Flow Regulator to 0.
9. De-isolate the High-Pressure Sensor and Purge Outlet Valve.
10.Connect a differential manometer to the test points on the flow sensor.
11.To check sensor calibration
• Raise the internal pressure by turning the CLAPS regulator clockwise until the Low-Pressure Alarm
Indicator turns green. This will activate the Purge Flow regulator & Purge Outlet Valve. The pressure will
fluctuate as the Purge Outlet Valve opens/closes. This is normal.
• Gradually open the Purge Flow Regulator until System Purging Indicator flashes yellow.
• Gradually close Purge Flow Regulator Valve until the purging indicator stops flashing yellow.
• Take a reading from pressure gauge.
12.To set the purge flow rate:
• Raise the internal pressure by turning the CLAPS regulator clockwise until the Low-Pressure Alarm
Indicator turns green. This will activate the Purge Flow regulator & Purge Outlet Valve. The pressure will
fluctuate as the Purge Outlet Valve opens/closes. This is normal.
• Gradually open the Purge Flow Regulator until System Purging Indicator flashes yellow.
• The flashing yellow indicator confirms the timer has started.
• The differential pressure should be greater than 6.4 mbarg.
• The relief valve is supplied with different orifice plates for the specified flow rate. This orifice plate is
held in position by two M3 screws and can easily be changed by removing the large cover plate from over
the outlet valve assembly and screws.
Warning: When opening the Purge Flow Regulator, ensure the over pressure within the enclosure
does not exceed the pressure relief valve setting.
13.The purge timer will start as soon as the Purging Indicator flashes yellow . Check that the time delay
between the indicator turning to
yellow (flashing)
and returning to
black
is not less than the minimum
time required for complete purging of the pressurized enclosure. Times in excess of minimum are
permitted.
14.After the purge has been completed, the Purge Outlet Valve will close and the air flow into the pressurized
enclosure will be controlled by the CLAPS Regulator. The initial setting may be too high or too low.
15.Gradually turn the CLAPS Regulator anti-clockwise to reduce enclosure pressure.
16.Reduce regulator until intermediate sensor causes contacts to open.
17.Check reading on manometer matches calibration label on pressure sensor.
18.Continue to reduce the CLAPS Regulator to test the minimum pressure sensor.
19.To check operation of Minimum Pressure Sensor, check readings on manometer as system will
automatically re-purge when it reaches minimum pressure.
20.While the system re-purges, return the CLAPS Regulator to the initial setting.
21.If minimum pressure is below the set point, refer to the Recalibration section
22.If the setting is too high, continual rising and falling of the enclosure pressure will be seen as the CLAPS
Regulator automatically shuts off and reinstates the flow. The CLAPS Regulator should be adjusted to
reduce the flow into the pressurized enclosure by turning the adjuster screw anti-clockwise.
23.If the initial setting is too low the CLAPS Regulator may not provide enough air flow causing a gradual
decline in enclosure pressure. To increase the flow into the pressurized enclosure, adjust the CLAPS
Regulator Relief Valve unit by turning the adjuster screw clockwise.