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NOTE: SMACNA Thermoplastic Duct (PVC) Construction
construction and installation requirements for round
and rectangular PVC ductwork for positive and
up to 27 degrees C at 498 Pa, 1493 Pa, and 2488 Pa
80 degrees F at 2 inches, 6 inches, and 10 inches
water gage. The requirements of this standard are
applicable specifically to Classes 12454-B and
12454-C PVC compounds as defined in ASTM D 1784,
Rigid Poly(Vinyl Chloride) (PVC) Compounds and
Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds.
The designer shall indicate on the drawings the
static pressure classification (498 Pa, 1493 Pa, or
2488 Pa 2 inches, 6 inches, or 10 inches water gage
positive or negative) to which each duct system (or
each portion of a duct system) is to be constructed.
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2.11.1
Ductwork
Construct ductwork, fittings, hoods, and accessories in accordance with
SMACNA TDCM and NFPA 91. Fabricate supplementary steel in accordance with
the AISC 335.
2.11.2
Product Requirements
Provide duct system from a manufacturer recognized in the field of
fabrication of PVC material. Fabricating personnel shall be certified by
the manufacturer as qualified to perform the work in accordance with the
specified requirements.
2.11.3
Basic Ductwork Materials
Fabricate ducts, hoods, accessories and components in sheet form from
materials conforming to ASTM D 1927, [Type I, Grade 1] [Type I, Grade 2].
Utilize extrusions of the same compounds as specified for duct. Solvent
cement shall conform to ASTM D 2564. Construct metal components, when
permitted to be located interior to the duct, of [Type] [304 or 304L] [316
or 316L] [_____] [corrosion resistant steel] [_____].
2.11.4
Fasteners
Where penetration of duct surfaces is approved or specified, provide Type
316 corrosion resistant steel fastener assemblies encapsulated with
polyester on duct interior, unless total disassembly is intended. Provide
flange fastener bolts and nuts of hex type only, cadmium plated, unless
exposed to corrosive fumes; in which case provide Type 316 stainless steel.
Equip bolted assemblies with two oversized washers, except where assembled
with metallic reinforcement contact. Plastic bolting is prohibited.
2.11.5
Joint Gaskets
Provide [3 mm1/8 inch thick acid resistant chloroprene.] [3 mm1/8 inch
thick Buna N.]
SECTION 15801N
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