Tank Construction; Relief Valve; Cathodic Protection - Lochinvar Commercial Electric Water Heaters Installation And Service Manual

INLET AND OUTLET CONNECTIONS
For ease of service, install unions on the cold water inlet
and hot water outlet of the water heater. The cold water
inlet connection is located on the lower left front side of the
water heater. A manual shutoff valve should be installed
upstream on the cold water source as an isolation device.
The hot water outlet connection is located on the top center
of the water heater. A manual shutoff valve should be
installed downstream on the hot water outlet source as an
isolation device in case the water heater must be
disconnected from the system.
STORAGE TANK
This appliance uses a glass lined steel storage tank to store
the heated water for use. The storage tank is constructed
in accordance with the requirements of the Underwriters
Laboratory Listing for a commercial electric water heater.
The tank is furnished with threaded connections for cold
water inlet, hot water outlet, a relief valve and a drain
connection. The storage tank has a hand hole for ease of
inspection, cleanout and service.
storage tank is glass lined and fired to 1600˚F (871˚C) to
insure a molecular fusing of glass and steel to protect the
steel base metal against corrosion. A magnesium anode is
standard to help prevent dissipation of the tank material by
electrolytic action.

RELIEF VALVE

This water heater is supplied with a temperature and
pressure relief valve(s) sized in accordance with ASME
Boiler and Pressure Vessel Code, Section IV. Some water
heaters may be supplied with an optional pressure only
relief valve. The relief valve(s) is installed in the vertical
position and mounted in the tapping provided in the
storage tank. No valve is to be placed between the relief
valve, and the water heater. To prevent water damage, the
discharge from the relief valve must be piped to a suitable
floor drain for disposal when relief occurs. No reducing
couplings or other restrictions shall be installed in the
discharge line. The discharge line shall allow complete
drainage of the valve and line. Relief valves should be
manually operated at least once a year. A relief valve that
fails to completely reseat and continues to discharge water
must be immediately replaced with a new, properly sized,
temperature and pressure relief valve.
A relief valve that discharges periodically may be due to
thermal expansion in a closed system. Many water systems
are equipped with pressure reducing valves, check valves or
back flow preventers which may cause the water system to
be closed. As water is heated it will expand in volume due
to thermal expansion. The system must make allowance for
this expansion. If an expansion tank is not provided in the
system, water pressure may increase to the point where the
water heater's temperature and pressure relief valve opens
to relieve the excess pressure.
pressure relief valve is not intended for the constant relief of
thermal expansion. This is an unacceptable condition and
The interior of the
must be corrected. Do not plug or cap the relief valve
discharge! A properly sized expansion tank is typically
installed in the potable water system to relieve the pressure
built up by thermal expansion of heated water. Consult
your local plumbing contractor and plumbing wholesaler
for assistance in properly selecting an expansion tank for
your system.
As the water heater operates, there may be noises generated
by the expansion and contraction of the metal parts of the
water heater and related piping. These noises may occur
during periods of heat up or cool down. They do not
represent harmful or dangerous conditions.
Hydrogen gas can be produced in a hot water system that
has not been used for a long period of time (generally two
weeks or more). Hydrogen gas is extremely flammable. To
prevent the possibility of injury under these conditions, we
recommend the hot water faucet be open for several
minutes at a sink close to the water heater before you use
any electrical appliance which is connected to the hot water
system. If hydrogen is present, there will be an unusual
sound such as air escaping through the pipe as the hot
water begins to flow. There should be no smoking or open
flames near the faucet at the time it is open.
5
CAUTION
Avoid contact with hot discharge water. Insure that
no one is in front of or around the relief valve
discharge line. Make sure that the extremely hot
water manually discharged from the relief valve will
not cause bodily injury or property damage.
THERMAL EXPANSION
OF WATER

CATHODIC PROTECTION

The temperature and