Chapter - 3
MNL000442.doc
Revision 00
09/19/2016
© Versum Materials, Inc. as of the revision and date shown. All rights reserved.
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NOTE: The systems are not Explosive Atmospheres Directive
approved for use in the European community.
Typically this supply is taken from a houseline nitrogen source. A 1/4" Swagelok
®
connection at the back of the controller is provided for the pneumatic supply inlet
connection as shown in Figure 3.5. Piping for the pneumatic supply must be
protected from mechanical damage. Maximum allowable working pressure is 100
psig (6.9 barg). Over-pressurization protection, such as a safety relief valve, must
be provided for the internal solenoids.
3.6.1 Z-purge Procedure
The Z purge pressure is controlled by a needle valve at rear of controller. After
opening the controller in a suspected hazardous area it is necessary to use the
following procedure to re-establish the Z-purge before operating the controller:
1.
Close the controller front and tighten both latches completely.
2.
Open the needle valve 4 to 5 turns (counter-clockwise). Allow the controller to
purge for 20 minutes.
3.
Adjust needle valve to satisfy the “Z-Purge” alarm (approximately 2 total turns
open).
Flow requirements to operate the solenoid valves are very small, less than 1 LPM
(2 CFH). If Type Z purge is required, a flow rate of 3-10 LPM (6-21 CFH) will be
needed, depending on the tightness of the individual controller and the installation.