SGB VLXE Ex M Series, Documentation

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28/07/2020
VACUUM-LEAK DETECTOR VLXE .. Ex M and VLXE .. Ex MMV - 37 -
(3) Close the needle valve of the testing device.
(4) Turn three-way valve 20 90° (CCW) and three-way valve 21 90°
(CW) so that the interstitial space is disconnected.
The interstitial space volume is now simulated by the test tank.
(5) The operational vacuum is now established in the test tank.
(6) Ventilate using the needle valve, check switching values “Pump
ON” and “Alarm ON” (visual and acoustic, if necessary). Record
the values.
(7) Press the “Audible alarm” button if necessary.
(8) Slowly close the needle valve and check switching values “Alarm
OFF” and “Pump OFF”.
(9) The unit passes the test if the measured switching values fall
within the specified tolerance.
(10) Turn back three-way valves 20 and 21 and remove the testing
device.
7.3.5 Testing the pump delivery pressure
The test of the delivery pressure of the pump is carried out in order to
determine if the vacuum source is capable of establishing the operat-
ing vacuum in the interstitial space.
(1) Attach measuring gauge to connection on three-way valve 20
and turn valve 90° (CCW).
(2) The pump is usually not running at this moment, i.e., the pres-
sure sensor must be vented to start the pump.
(3) Turn three-way valve 21 90° (CW). The pressure sensor is vent-
ed, the pump starts (and the alarm is triggered, acknowledge if
necessary).
(4) This unit passes the test if the suction height of the vacuum
pump is at least 40 mbar higher than the switching value “Pump
OFF” (i.e., the operational vacuum).
(5) Once the test is complete, return valves to their original positions
and remove the measuring gauge.
7.3.6 System Tightness Test
(1) The system tightness requirement is defined in Section 6.1.
Determine the test period for each interstitial space connected
(and/or the entire monitored system) (calculate or use test re-
ports prepared by SGB GmbH).
(2) Attach the measuring gauge to the connection on three-way
valve 21 and turn valve 180°.
(3) Read off and record starting vacuum and time. Wait for the test
period to elapse and determine the vacuum drop.
21 20
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Functional Check and Maintenance