Chapter 5 - Features and Components
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06/25/2019
Chemical Equipment
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Confidential and Proprietary Data
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5.3.2 System Combustible Vapor Detection (Required)
A combustible vapor detector is located near the exhaust flow stream of the ChemGuard®.
When combustible chemical vapors come from the inner ChemGuard® cabinet, a VAPOR
Alarm is activated.
This alarm will terminate any operation in progress, and will return all valves to their safe
(deactivated) condition to prevent further chemical flow.
The vapor pressures of many process chemicals used in the ChemGuard® are too low to be
detected by the vapor detector, and also are too low to be in their flammable/combustible
ranges. However, most are air-sensitive chemicals that will develop byproducts detectable by
the combustible vapor detection system.
NOTE
: The combustible vapor detection system is not designed for use in detecting
Threshold Limit Value (TLV) concentrations of process chemical. The customer is
responsible for determining whether such protection is required and for providing this
equipment. Refer to Chapter 7 for vapor detector calibration and maintenance.
5.3.3 Hazardous Vapor Sniffer Port
There is a sniffer port located on the display door of the cabinet enclosure as shown in the
below figure. In an event where the chemical containment is in question or the internal
cabinet atmosphere needs to be verified, removal of the sniffer port screw can allow access
for a customer approved gas detector to be inserted.
WARNING
Always wear proper PPE for hazardous atmosphere when the cabinet internal atmosphere is in question or
unknown. THIS PORT IS NOT TO BE USED WHEN FLAMMABLE OR TOXIC ATMOSPHERE IS KNOWN TO EXIST
INSIDE CABINET.
