Fire Code of the Philippines Ebook - SafetySignsPH.com Fire Code of the Philippines eBook - SafetySignsPH | Page 368

as in removing flammable vapors, mists or powders to a safe location
and capable of confining and controlling combustible residues, dusts
and deposits.
15. Mechanical ventilation shall be kept in operation at all times, while
spraying operations are being conducted and for a sufficient time
thereafter to allow vapors from drying coated particles and dry
finishing material residues to be exhausted. Where spray operations
are conducted automatically without an operator constantly on duty,
the operating controls shall be arranged that the spray apparatus
cannot function unless exhaust fans are operating.
16. Each spray booth shall have an independent exhaust duct system
discharging to the exterior of the building. However, multiple cabinet
spray booths in which identical spray finishing material is used with a
combined frontal area of not more than one and sixty-seven
hundredths square meters (1.67 m 2 ) may have a common exhaust. If
more than one (1) fan serves one (1) booth, all fans shall be
interconnected that one (1) fan cannot operate without operating all.
17. Electric motors driving exhaust fans shall not be placed inside booths
or ducts. Fan rotating elements shall be non-ferrous or non-sparking or
the casing shall consist of, or be lined with, such material. There shall
be ample clearance between the fan-rotating element and the fan
casing to avoid a fire by friction, necessary allowance being made for
ordinary expansion and loading to prevent contact between moving
parts and the duct or fan housing. Fan blades shall be mounted on a
shaft sufficiently heavy to maintain perfect alignment even when the
blades of the fan are heavily loaded, with the shaft preferably to have
bearings outside the duct and booth. All bearings shall be of the self-
lubricating type, or lubricated from the outside duct.
18. Belts shall not enter the duct or booth unless belt and pulley within the
duct or booth are tightly enclosed.
19. Exhaust ducts shall be constructed of steel having a thickness not less
than that indicated in Table 29 and shall be substantially supported:
Table 29: MINIMUM THICKNESS OF SPRAY BOOTH
EXHAUST DUCTS, BY DIAMETER
Diameter of duct
Minimum thickness
20 cms or less
20 to 46 cms inclusive
46 to 76 cms inclusive
Over 76 cms
352
(0.60 mm)
(0.75 mm)
(0.90 mm)
(1.20 mm)