HOT WATER
OUTLET
12” TO 15”
TEMPERED WATER
OUTLET
COLD |
| CHECK |
WATER |
| VALVE |
INLET |
| MIXING |
| CHECK | |
| VALVE | |
| VALVE | |
|
| |
| TO TANK | |
| INLET |
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. Where this is done, the circulation should be very gentle so that it does not cause any unnecessary turbulence inside the water heater. The circulation should be just enough to provide 180°F (82°C) water at the point of
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
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 19 and the Water Piping Diagrams beginning on page 34.
Temperature-Pressure Relief Valve
Explosion Hazard
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
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
For safe operation of the water heater, the
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