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TEMPERED WATER
OUTLET
COLD
WATER
INLET
FIGURE 10.
DISHWASHING MACHINES
All dishwashing ma hines meeting the National Sanitation
Foundation requirements are designed to operate with water
flow pressures between 15 and 25 pounds per square in h
(103 kPa and 173 kPa) Flow pressures above 25 pounds
per square in h (173 kPa), or below 15 pounds per square
in h (103 kPa), will result in improperly sanitized dishes
Where pressures are high, a water pressure redu ing or flow
regulating ontrol valve should be used in the 180 F (82 C)
line to the dishwashing ma hine and should be adjusted to
deliver water pressure between these limits
The National Sanitation Foundation also re ommends
ir ulation of 180 F (82 C) water The ir ulation flow rate
should be just enough to provide 180 F (82 C) water at the
point of take-off to the dishwashing ma hine
Adjust flow by throttling a full port ball valve installed in
the
ir ulating line on the outlet side of the pump Never
throttle flow on the su tion side of a pump See Water Piping
Diagrams in this manual
CLOSED WATER SYSTEMS
Water supply systems may, be ause of ode requirements or
su h onditions as high line pressure, among others, have
installed devi es su h as pressure redu ing valves, he k
valves, and ba k flow preventers Devi es su h as these
ause the water system to be a losed system
THERMAL EXPANSION
As water is heated, it expands (thermal expansion) In a
losed system the volume of water will grow when it is heated
As the volume of water grows there will be a orresponding
in rease in water pressure due to thermal expansion Thermal
expansion an ause premature tank failure (leakage) This
type of failure is not
overed under the limited warranty
Thermal expansion an also ause intermittent Temperature-
Pressure Relief Valve operation water dis harged from the
valve due to ex essive pressure build up This ondition is
not overed under the limited warranty The Temperature-
Pressure Relief Valve is not intended for the onstant relief
of thermal expansion
HOT WATER
OUTLET
12" TO 15"
(30-38 cm)
CHECK
VALVE
MIXING
CHECK
VALVE
VALVE
TO TANK
INLET
A properly sized thermal expansion tank must be installed on
all
losed systems to
expansion Conta t a lo al plumbing servi e te hni ian to have a
thermal expansion tank installed
See Water Line Conne tions on page 19 and the Water Piping
Diagrams beginning on page 35
TEMPERATURE-PRESSURE RELIEF VALVE
This water heater is provided with a properly rated/sized and erti ed
ombination Temperature-Pressure Relief Valve (T&P valve) by
the manufa turer The valve is erti ed by a nationally re ognized
testing laboratory that maintains periodi inspe tion of produ tion
of listed equipment of materials as meeting the requirements for
Pressure Relief Valves for Hot Water Supply Systems, ANSI Z21 22
CSA 4 4, and the ode requirements of ASME
If repla ed, the new T&P valve must meet the requirements
of lo al odes, but not less than a ombination Temperature-
Pressure Relief Valve rated/sized and erti ed as indi ated in
the above paragraph The new valve must be marked with a
maximum set pressure not to ex eed the marked hydrostati
working pressure of the water heater (150 psi
a dis harge apa ity not less than the water heater Btu/hr or kW
input rate as shown on the water heater s model rating label
NOTE In addition to the fa tory installed Temperature-Pressure
Relief Valve on the water heater, ea h remote storage tank that
may be installed and piped to a water heating applian e must also
have its own properly sized, rated and approved Temperature-
Pressure Relief Valve installed Call the toll free te hni al
support phone number listed on the ba k over of this manual
for te hni al assistan e in sizing a Temperature-Pressure Relief
Valve for remote storage tanks
For safe operation of the water heater, the Temperature-Pressure
Relief Valve must not be removed from its designated opening
nor plugged The Temperature-Pressure Relief Valve must be
installed dire tly into the tting of the water heater designed for
the pressure relief valve
dis harge will exit the pipe within 6 in hes (15 2 m) above an
adequate oor drain, or external to the building In old limates
it is re ommended that it be terminated at an adequate drain
inside the building Be ertain that no onta t is made with any
live ele tri al part The dis harge opening must not be blo ked
or redu ed in size under any ir umstan es Ex essive length,
over 30 feet (9 14 m), or use of more than four elbows an ause
restri tion and redu e the dis harge apa ity of the valve
14
ontrol the harmful effe ts of thermal
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.
1,035 kPa) and
Install dis harge piping so that any
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