TYPICAL INSTALLATION
MIXING VALVE / THERMAL EXPANSION TANK USAGE AND SPACE HEATING
FIGURE 2.
Mixing Valves
Mixing valves are available at plumbing supply stores. Consult a Qualified Installer or ServiceAgency. Follow mixing valve manufacturer’s instructions for installation of the valves.
DANGER
Water temperature over 125°F (52°C) can cause severe burns instantly resulting in severe injury or death.
Children, the elderly and the physically or mentally disabled are at highest risk for scald injury.
Feel water before bathing or showering.
Temperature limiting devices such as mixing valves must be installed when required by codes and to ensure safe temperatures at fixtures.
| TABLE 1. | |
| Water Temperature |
| Time to Produce 2nd & 3rd |
| Degree Burns on Adult Skin | |
|
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180°F (82°C) |
| Nearly instantaneous |
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|
170°F (77°C) |
| Nearly instantaneous |
160°F (71°C) |
| About 1/2 second |
150°F (66°C) |
| About |
140°F (60°C) |
| Less than 5 seconds |
130°F (54°C) |
| About 30 seconds |
120°F (49°C) |
| More than 5 minutes |
|
|
|
Water heated to a temperature which will satisfy clothes washing, dish washing, and other sanitizing needs can scald and cause permanent injury upon contact. Short repeated heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the water heater’s temperature setting by up to 20°F (11°C).
Some people are more likely to be permanently injured by hot water
than others. These include the elderly, children, the infirm and the
physically/mentally disabled. Table 1 shows the approximate time-
provided by the water heater being installed fits into one of these
groups or if there is a local code or state law requiring a certain water temperature at the point of use, then special precautions must be taken.
In addition to using lowest possible temperature setting that satisfies demand
of application a Mixing Valve should be installed at water heater (see Figure 3) or at hot water taps to further reduce system water temperature.
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| HOT WATER | |||
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| OUTLET |
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| 12” TO 15” | ||
TEMPERED WATER |
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| OUTLET |
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COLD |
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| CHECK | ||
WATER |
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| VALVE | ||
INLET |
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| MIXING | ||
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| CHECK | |||
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| VALVE | |||
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| VALVE | |||
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TO TANK
INLET
FIGURE 3.
9
