Thermal expansion – State Series 301 User Manual
Page 16

16
METAL
DRAIN PAN
1 3/4” DEPTH MAXIMUM
FLOOR DRAIN
DRAIN LINE 3/4”
ID MINIMUM
DISCHARGE PIPE
DO NOT CAP OR PLUG
TEMPERATURE AND PRESSURE RELIEF VALVE
IN A CLOSED SYSTEM, USE A
THERMAL EXPANSION TANK
COLD WATER
SUPPLY TO FIXTURES
COLD WATER
INLET VALVE
(SHUT-OFF VALVE)
PRESSURE REDUCING
VALVE WITH BYPASS
UNION
HOT WATER
OUTLET
MASSACHUSSETTS:
INSTALL A VACUUM RELIEF
IN COLD WATER LINE PER
SECTION 19 MGL 142.
MAIN WATER SUPPLY
6” MAXIMUM
AIR GAP
1” MINIMUM
FIGURE 13.
COLD
WATER
INLET
HOT
WATER
OUTLET
TEMPERED WATER
TO FIXTURES
MIXING VALVE
(SET TO 120°F)
FOLLOW THE MIXING
VALVE MANUFACTURER’S
INSTRUCTIONS
UNTEMPERED
HOT WATER
FIGURE 14.
Please note the following:
•
The system should be installed only with piping that is
suitable for potable (drinkable) water such as copper,
CPVC, or polybutylene. This water heater must not be
installed using iron piping or PVC water piping.
•
Use only pumps, valves, or fittings that are compatible
with potable water.
•
It is recommend that only full flow ball or gate valves
are used in water piping installations. The use of valves
that may cause excessive restriction to water flow is not
recommended.
•
Use only 95/5 tin-antimony or other equivalent solder.
Any lead based solder must not be used.
•
Piping that has been treated with chromates, boiler seal,
or other chemicals must not be used.
•
Chemicals that may contaminate the potable water
supply must not be added to the piping system.
Thermal Expansion
As water is heated, it expands (thermal expansion). In a closed system,
the volume of water will increase. As the volume of water increases,
there will be a corresponding increase in water pressure due to thermal
expansion. Thermal expansion can cause premature tank failure
(leakage). This type of failure is not covered under the limited warranty.
Thermal expansion can also cause intermittent temperature-pressure
relief valve operation: water discharged from the valve due to excessive
pressure build up. The temperature-pressure relief valve is not intended
for the constant relief of thermal expansion. This condition is not covered
under the limited warranty.
A properly-sized thermal expansion tank should be installed on all closed
systems to control the harmful effects of thermal expansion. Contact a
plumbing service agency or your retail supplier regarding the installation
of a thermal expansion tank.