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General informatio, General information, General safety – Raypak MVB 503-2003 User Manual

Page 7: Time/temperature relationships in scalds

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7

GENERAL SAFETY

To meet commercial hot water use needs, the high

limit safety control on this water heater will shut off the

main gas valve before the outlet temperature reaches

210°F. However, water temperatures over 125°F can

cause instant severe burns or death from scalds.

When supplying general purpose hot water, the rec-

ommended initial setting for the temperature control is

125°F.

This section applies to Hot Water Supply Boilers and

Hot Water Heaters ONLY. For sanitary rinse applica-

tions where outlet temperatures of 180°F to 195°F are

required, a boiler is recommended since the 210°F

limit on water heaters will NOT allow the heater to

maintain these desired sanitary rinse temperatures.

Safety and energy conservation are factors to be con-

sidered when setting the water temperature on the

thermostat. The most energy-efficient operation will

result when the temperature setting is the lowest that

satisfies the needs of the application.

Water temperature over 125°F can cause instant

severe burns or death from scalds. Children, disabled

and elderly are at highest risk of being scalded.

Feel water before bathing or showering.

Temperature limiting valves are available.

Maximum water temperatures occur just after the

heater’s burner has shut off. To determine the water

temperature being delivered, turn on a hot water

faucet and place a thermometer in the hot water

stream and read the thermometer.

NOTE: When this water heater is supplying general

purpose hot water for use by individuals, a

thermostatically controlled mixing valve for reducing

point of use water temperature is recommended to

reduce the risk of scald injury. Contact a licensed

plumber or the local plumbing authority for further

information.

Water temperature over 125°F can
cause instant severe burns or death
from scalds.

Children, disabled, and elderly are
at highest risk of being scalded.

See instruction manual before set-
ting temperature at water heater.

Feel water before bathing or show-
ering.

Temperature limiting valves are
available, see manual.

Time/Temperature

Relationships in Scalds

The following chart details the relationship of water

temperature and time with regard to scald injury and

may be used as a guide in determining the safest

water temperature for your applications.

Water

Temp.

Time to Produce Serious

Burn

120°F

More than 5 minutes

125°F

1-1/2 to 2 minutes

130°F

About 30 seconds

135°F

About 10 seconds

140°F

Less than 5 seconds

145°F

Less than 3 seconds

150°F

About 1-1/2 seconds

155°F

About 1 second

Table courtesy of The Shriners Burn Institute

Table B: Time to Produce Serious Burn