Chapter 3 - Tubing Connections
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MNL000297.doc
Revision 2
09/16/2016
Source System TE11
© Versum Materials, Inc. as of the revision and date shown. All rights reserved.
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3.6
Pneumatic Supply
A nitrogen (or compressed clean dry air) source is required for this system for pneumatic valve
operation. This nitrogen supply needs to be regulated to 85-95 psig (5.9-6.6 barg). The flow rate
required for pneumatic valve operation is negligible. If compressed air is used as the pneumatic
source, the compressor shall be located in a non-classified area. If the air intake line for the
compressor passes through a classified location, the line shall be made of a non-combustible material
designed to prevent leakage and protect against mechanical damage. If electrical power for the purge
air is required, this power shall be on a separate disconnect or before the gas
source system
disconnect.
This supply is also used for Type Z purge of the electrical enclosure. The Type Z purge is required to
maintain a positive pressure at or above 0.1" H
2
O (24.9 Pa). This is in accordance with Article 496 of the
National Fire Protection Agency (NFPA) regulations. In applications where Type Z purge is required, the
controller will be equipped with a pressure switch to monitor the pressure. The Type Z purge will require
a flow rate of approximately 2.5-2.8 LPM (5-6 CFH).
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.