TM 9-4940-444-14 & P
EXHAUST PIPING INSTRUCTIONS - cont.
L. Location of Piping.
Header pipe should be located above the equipment exhausted whenever possible and supported from ceiling or
All piping shall be kept at least 6" away from combustible parts of the building structure.
3. Fire Walls:
Pipe systems should not extend through fire walls unless necessary and in such cases, fusible link pipe shutters
shall be provided on each side of the fire wall - preferably of the verticle type described in the code of the National
Fire Protection Association on blower systems.
M. Fire and Explosion Hazards.
1. Electrical Ground:
Any exhaust system handling matter of an explosive nature shall have the piping and other equipment
permanently grounded through electrical conductors.
2. Non-Ferrous Construction:
Exhaust systems handling highly flammable or explosive matter shall have such parts of the system, that are
exposed to being hit be metallic objects, made from non-ferrous materials to prevent the possibility of sparks.
Fan impellers in such installations shall be made entirely of non-ferrous material and in extremely hazardous
operation the fan housing shall be constructed of non-ferrous material. in all other respects, the system shall meet
the minimum requirements of the code on blower systems prepared by the National Fire Protection assoc.