sentence.
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Coil shall conform to the provisions of ARI 410. Coil shall be
fin-and-tube type constructed of seamless copper tubes and [aluminum] [or]
[copper] fins mechanically bonded or soldered to tubes. Headers shall be
constructed of cast iron, welded steel or copper. Coil shall be
constructed to float within the casing to allow free expansion and
contraction of tubing. Casing and tube support sheets shall not be lighter
than 1.6 mm (16 gauge) 16 gauge galvanized steel formed to provide
structural strength. When required, multiple tube supports shall be
provided to prevent tube sag. Coil shall be circuited for suitable water
velocity without excessive pressure drop and properly pitched for drainage
where required or indicated. Each coil shall be tested at the factory
under water at not less than 2000 kPa 300 psi air pressure, tested
hydrostatically after assembly of the unit and proved tight under a gauge
pressure of 1400 kPa 200 psi. Coil shall be suitable for use with water up
to 120 degrees C 250 degrees F. Coil shall allow complete coil drainage
with a pitch of not less than 10 mm/meter 1/8 inch/foot slope to drain.
2.10.3.2
Steam Coil
Coil shall conform to the provisions of ARI 410. Coil shall be constructed
of cast semi-steel, welded steel, or copper headers, red-brass or copper
tubes, and copper or aluminum fins mechanically bonded or soldered. Tubes
shall be rolled and bushed and brazed or welded into headers. Coil casings
and tube support sheets, with collars of ample width, shall be not lighter
than 1.6 mm (16 gauge) 16 gauge galvanized steel, formed to provide
structural strength. When required, multiple tube supports shall be
provided to prevent tube sag. The fin tube and header section shall float
within the casing to allow free expansion of tubing for coils subject to
high pressure-steam service. Coils shall be factory pressure tested and
capable of withstanding 1700 kPa 250 psi hydrostatic test pressure or 1700
kPa 250 psi air pressure, and be for [700] [1400] kPa [100] [200] psi steam
working pressure. Preheat coils shall be steam-distributing tube type.
Condensing tubes shall be not less than 15 mm 5/8 inch outside diameter.
Distribution tubes shall be not less than 10 mm 3/8 inch outside diameter,
and be equipped with orifices to discharge steam to condensing tubes.
Distribution tubes shall be installed concentrically inside of condenser
tubes and be held securely in alignment. The maximum length of a single
coil shall be limited to 120 times the diameter of the outside tube. Other
heating coils shall be minimum 13 mm 1/2 inch outside diameter single-tube
type. Supply headers shall distribute steam evenly to all tubes at the
indicated steam pressure. Coil shall allow complete coil drainage with a
pitch of not less than 10 mm/meter 1/8 inch/foot slope to drain.
2.10.3.3
Electric Heating Coil
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NOTE: Choose the second set of brackets if an
air-conditioning unit for EDP is specified.
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Coil shall be an electric duct heater in accordance with UL 1995 and NFPA 70.
Coil shall be duct- or unit-mounted. Coil shall be of the [nickel
chromium resistor, single stage, strip] [nickel chromium resistor, single
stage, strip or stainless steel, fin tubular] type. Coil shall be provided
with a built-in or surface-mounted high-limit thermostat interlocked
electrically so that the coil cannot be energized unless the fan is
SECTION 15700A
Page 38
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