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ES&H
Manual Flammable
Gas Supplement |
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Chapter
4 Electrical Classification
Guidelines |
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These
guidelines are based on common gas system installations at Jefferson Lab which
have been analyzed. The classification shall be determined for each specific
installation. All areas are assumed to
be NEC Class 1, Group D.
1) Enclosed gas storage and mixing
sheds are Division 2. This is based on adequate ventilation, this standard, and
that a flammable mixture is likely to be present in the atmosphere less than
ten hours per year.
2) A sphere with a diameter of 1.5
meters around outdoor vents is Division 1. A sphere with a diameter of 3 meters
is Division 2. Generally there would be
no electrical equipment in this area.
3) A sphere with a diameter of 1
meter is Division 1 around indoor vents. A sphere with a diameter of 2 meters
is Division 2.
Revision
Summary
Periodic Review 05/06/16 No changes per TPOC
Revision 1.0 06/15/11 New content
TECHNICAL POINT-OF-CONTACT |
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