State SBN85 390NE A - Manual (Page 13)

13
HOT WATER
OUTLET
TO TANK
INLET
CHECK
VALVE
MIXING
VALVE
COLD
WATER
INLET
TEMPERED WATER
OUTLET
12” TO 15”
(30-38 cm)
CHECK
VALVE
figure 10.
dishwashing maChines
All dishwashing machines meeting the National Sanitation
Foundation requirements are designed to operate with water
flow pressures between 15 and 25 pounds per square inch
(103 kPa and 173 kPa). Flow pressures above 25 pounds
per square inch (173 kPa), or below 15 pounds per square
inch (103 kPa), will result in improperly sanitized dishes.
Where pressures are high, a water pressure reducing or
flow regulating control valve should be used in the 180°F
(82°C) line to the dishwashing machine and should be
adjusted to deliver water pressure between these limits.
The National Sanitation Foundation also recommends
circulation of 180°F (82°C) water. The circulation should be just
enough to provide 180°F (82°C) water at the point of take-off to
the dishwashing machine.
Adjust flow by throttling a full port ball valve installed in the
circulating line on the outlet side of the pump. Never throttle flow
on the suction side of a pump. See Water Piping Diagrams in
this manual.
Closed water systems
Water supply systems may, because of code requirements
or such conditions as high line pressure, among others, have
installed devices such as pressure reducing valves, check
valves, and back flow preventers. Devices such as these cause
the water system to be a closed system.
thermal expansion
As water is heated, it expands (thermal expansion). In a closed
system the volume of water will grow when it is heated. As the
volume of water grows 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. This condition is not covered under the
limited warranty. The Temperature-Pressure relief Valve is not
intended for the constant relief of thermal expansion.
A properly sized thermal expansion tank must be installed on
all closed systems to control the harmful effects of thermal
expansion. Contact a local plumbing service agency to have a
thermal expansion tank installed.
See Water line Connections on page 20 and the Water Piping
Diagrams beginning on page 35.
temperature-pressure relief ValVe
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.
This water heater is provided with a properly rated/sized and
certified combination Temperature-Pressure relief Valve (T&P
valve) by the manufacturer. The valve is certified by a nationally
recognized testing laboratory that maintains periodic inspection
of production of listed equipment of materials as meeting the
requirements for relief Valves for hot Water Supply Systems,
ANSI Z21.22 • CSA 4.4, and the code requirements of ASMe.
If replaced, the new T&P valve must meet the requirements
of local codes, but not less than a combination Temperature-
Pressure relief Valve rated/sized and certified as indicated in
the above paragraph. The new valve must be marked with a
maximum set pressure not to exceed the marked hydrostatic
working pressure of the water heater (150 psi = 1,035 kPa)
and a discharge capacity 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 factory installed Temperature-Pressure
relief Valve on the water heater, each remote storage tank
that may be installed and piped to a water heating appliance
must also have its own properly sized, rated and approved
Temperature-Pressure relief Valve installed. Call the toll free
technical support phone number listed on the back cover of
this manual for technical assistance 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 directly into the fitting of the water heater
designed for the relief valve. Install discharge piping so that
any discharge will exit the pipe within 6 inches (15.2 cm)
above an adequate floor drain, or external to the building. In
cold climates it is recommended that it be terminated at an
adequate drain inside the building. Be certain that no contact is
made with any live electrical part. The discharge opening must
not be blocked or reduced in size under any circumstances.
excessive length, over 30 feet (9.14 m), or use of more than
four elbows can cause restriction and reduce the discharge
capacity of the valve.