EXPO D760-ET MiniPurge, Manual

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ML548 | v11
Page
16
Expo Technologies UK
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E: sales@expoworldwide.com
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Expo Technologies China
T: +86 532 8906 9858
E: qingdao@expoworldwide.com
Re-calibration of the Relief Valve Unit
Warning
Incorrect adjustment of the Relief Valve Unit can lead to significant over pressure and result in
damage to the enclosure.
If maximum pressure setting is reached, stop adjustment, and reduce the pressure.
To perform the following adjustments, an 8 mm spanner (wrench) and a 2.5 mm hex key will be required.
Ensure that the Relief Valve Unit is free from contamination prior to making any adjustment. To do this:
• Remove large cover plate using an 8 mm spanner (wrench).
• Check that the interior and all components are clean and free from contamination.
• Replace large cover plate
To adjust the lift off pressure of the Relief Valve:
• Attach test equipment as described in the Commissioning Section.
• Remove small cover plate.
• Whilst holding the central adjustment screw in position using the hex key, loosen the retaining nut.
• Adjust the hex key clockwise to increase, or anti-clockwise to reduce the lift off pressure.
• Before testing, retighten the locking nut whilst holding the adjustment screw in place.
• Carry out the commissioning tests to check the correct setting of the relief valve after adjustment.
• The adjustment is sensitive, and it is recommended that a
1
/
4
turn (maximum) adjustments are applied
between tests.
Re-calibration of the Pressure Sensors
The brass nozzle on the sensor is sealed into position using Loctite thread sealant. If the thread has seized up,
remove to a safe area and heat slightly to soften prior to making any adjustment. This prevents potential
damage to the brass of the nozzle.
• Disconnect pipe work from the sensor, including pipe located below the sensor.
• Remove sensor by unscrewing anti-clockwise.
• The nozzle is located under the sensor.
• The adjustment is sensitive, turn the nozzle in
1
/
8
of a turn step.
• Turn clockwise to reduce the pressure setting and anti-clockwise to increase.
• Replace sensor, screwing clockwise.
• Reconnect all pipe work.
Orifice Plate
Allen Screw and Lock NUT
Removing the small cover plate
to set the RLV opening pressure