Hubbell Electric Heater Company T - Manual (Page 5)

5
SECTION I -
GENERAL DESCRIPTION AND CONSTRUCTION
GENERAL DESCRIPTION
This book describes a packaged boiler water powered indirect water heater that is a stationary, self-
contained unit. The complete assembly on a standard unit consists of the storage tank, immersion
heating coil, and an ASME rated combination temperature and pressure safety relief valve. Optional
equipment may be supplied with your unit. Please consult the product drawing for details specific to
your assembly. The unit is factory assembled, insulated, jacketed, wired, tested, and ready for electrical
and plumbing service connections.
CONSTRUCTION
TANK
The standard storage tank is constructed of steel and internally lined with specially formulated
Hydrastone cement to a ½-inch minimum thickness. The tank is designed for a maximum allowable
working pressure of 150 psi (300 psi TP).
TANK CONNECTIONS
The heater is supplied with separate cold water and hot water connections. Water entering the cold
water inlet is deflected by means of a baffle within the tank. The hot water outlet includes a built in heat
trap to prevent hot water from radiating out from the heater. A ¾-inch FNPT connection is located on
the side of the heater for mounting a combination safety temperature and pressure relief valve. An
overflow line should be installed from the relief valve outlet to a floor drain. A ¾-inch GHT connection
is supplied for draining. See drawing for locations and sizes.
OUTER SHELL AND INSULATION
The tank is encapsulated in 2-inch thick polyurethane foam insulation. The insulation is protected by a
high impact non-corroding colorized composite protective jacket.
HEATING COIL
The water heater is supplied with a high quality, factory installed, high efficiency, single walled,
copper finned heating coil designed for a maximum working pressure of 150 psi. The tubing is
installed in a heavy-duty fabricated steel head with threaded NPT connections. Each assembly is
fastened to a corresponding tank flange using a gasket and hex head steel bolts and nuts. Double
walled tubing may be supplied as an option.