Basic Documentation

Table Of Contents
Exhaust Systems
Siemens Industry, Inc. 133
Topic Requirement(s) Commentary
Configuration
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Longitudinal sections of a duct shall be a continuous seamless tube or of a
continuously welded formed sheet. Longitudinal seams that are formed mechanically
shall be utilized only for light duty systems with no condensation or accretion inside the
duct. Spiral ducts may be one gauge lighter than the required gauge of longitudinal
seam duct, except the spiral duct gauge shall always meet the abrasive wear
resistance requirements.
Traverse joints shall be continuously welded or flanged with welded or Van Stone
flanges. (When nonmetallic materials are used, joints shall be cemented in accordance
with the manufacturer’s procedures.) If the duct is coated with a corrosion-resistant
material, the coating may extend from the inside of the duct to cover the entire face of
the flange. Flange faces shall be gasketed or beaded with material suitable for the
service.
c. The following design and construction elements shall be considered:
All systems used to exhaust air potentially containing radioactive materials shall
have the ability to sample the effluent being discharged (primarily gasses and
vapors) and shall be prominently marked for ease of identification.
This sampling point shall be located inside an accessible mechanical room at a
point downstream from any exhaust treatment systems (filtration, etc.).
Where radioactive iodination is performed in specific laboratories, the exhaust
system serving those laboratories shall be equipped to accept appropriate charcoal
filtration systems.
Airborne radioactive effluent sampling systems shall be designed in accord with
ANSI Standard N13.1, Guide to Sampling Airborne Radioactive materials in
Nuclear Facilities. A single-nozzle sampling probe shall be designed to accomplish
sampling of gases and vapors, as specified in ANSI Standard N13.1
C.12.5 Building Vacuum Systems
a. Vacuum systems shall be protected with appropriate filtration (0.2 micron
hydrophobic filter or the equivalent) to minimize the potential for contamination of
vacuum pumps. Filters shall be on the suction side of pumps. Exhaust from vacuum
systems shall be routed to the main laboratory exhaust system. Chemical fume hood
or outside the facility. Vacuum system exhaust shall not be discharged into mechanical
rooms or recirculated into occupied areas.
b. Filters shall be located as close as possible to the laboratory in order to minimize
the potential contamination of vacuum lines, thus minimizing decontamination and
decommissioning costs.
c. Filter systems and housings shall be designed for easy filter replacement and
maintenance to reduce the potential for maintenance worker exposure and provide for
easy disposal.
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