Operating instructions

23
Domestic Piping
Temperature & Pressure (T&P) Relief Valve-
Storage Tank or SMART Installations
To reduce risk of excessive pressures and
temperatures in a storage tank or ACV-
Triangle Tube SMART I.F.W.H., install
temperature and pressure protective
equipment required by local codes, but no
less than a combination temperature and
pressure relief valve certified by a nation-
ally recognized testing laboratory that
maintains periodic inspection of produc-
tion of listed equipment or materials, as
meeting the requirements for Relief
Valves and Automatic Gas Shutoff
Devices for Hot Water Supply Systems,
ANSI Z21.22. This valve must be marked
with the maximum working pressure of
the domestic water heater (150 psi).
• The storage tank or SMART must be pro-
tected with a field supplied T&P relief valve.
• Size the T&P relief valve by the follow-
ing specifications, unless they conflict
with local codes: 3/4” NPT with an AGA
Rating of 124,000 BTU/hr.
T&P Relief Valve Discharge Piping
T&P relief valve discharge piping must be:
- made of material serviceable for tem-
peratures of 250ºF [121ºC] or greater
- directed so that hot water flows away
from all persons
- directed to a suitable place for disposal
- installed so as to allow complete draining
of the T&P relief valve and discharge line
T&P relief valve discharge piping MUST
NOT be:
- excessively long, using more than 2
elbows or 15 feet [4.5 m] of piping can
reduce discharge capacity
- directly connected to a drain, terminate
discharge piping within 6” [152 mm]
from drain, refer to local codes
- plugged, reduced or restricted
- subject to freezing
Do not install any valve between T&P
relief valve and the storage tank or
SMART connection or on T&P relief
valve discharge piping. Do not plug
T&P relief valve or discharge piping.
Improper placement and piping of T&P
relief valve can cause severe personal
injury, death or substantial property
damage.
Isolation valves are only intended for
servicing the domestic coil. During any
domestic service the appliance should be
turned off and the domestic coil drained
to prevent over pressurization of the
appliance’s domestic coil.
Drain Valves
Drain valves and fittings are field supplied.
Thermal Expansion
If a backflow preventer, check valve or pressure
reducing valve is installed on the cold water sup-
ply piping of the domestic water heater, install
an expansion tank on the cold water supply line
to prevent normal thermal expansion from
repeatedly forcing open the relief valve.
Relief valve is not intended for constant
duty, such as relief of pressure due to
repeated normal system water expansion.
Correct this condition by installing a
properly sized expansion tank in domes-
tic water system. Refer to expansion tank
manufacturer’s installation instructions
for proper sizing.
WARNING
CAUTION
WARNING
CAUTION