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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3.7.1 Exhaust Flow Clarifications and Definitions:
1.
Silane and disilane enclosures contain internal metal baffles, used to direct
exhaust flow across fittings. These internal metal baffles must not be
removed.
2.
High-impact polycarbonate baffles are not supplied, or available for the access
hatch of 1 cylinder standard flow cabinets, high flow Silane VMBs, or high
flow Disilane source VMB’s.
3.
Definitions:
Static pressure - The suction pressure provided by the exhaust system
measured near the entrance of the 6” (154 mm) round exhaust duct. Static
pressure does not provide a verification of exhaust flow. See velocity
pressure.
Velocity pressure - Moving air creates a force, or pressure component, that
can be measured by means of a pitot tube and differential pressure
measuring device such as a pressure switch or pressure transmitter. These
devices can be used to verify exhaust flow and provide a visual, digital, or
analog signal; they only provide an approximation of the exhaust flow rate.
They cannot provide an accurate measurement of exhaust flow due to their
location and air flow characteristics in the round exhaust duct located on the
enclosure.
High-impact polycarbonate baffle - A clear high-impact polycarbonate
window closing off 33% of the access hatch area when the window is
opened. This baffle reduces air flow requirements through the hatch.
Figure 3.6 shows the typical exhaust hook-up location. See the Installation
Drawing (INS) for specific location and size of exhaust duct on valve manifold
enclosure. An INS drawing is provided only if specifically requested by the
customer.
