Scalding; Water Chemistry; Piping Components - Lochinvar ARMOR 151 Installation And Operation Manual

6
System piping

Scalding

This water heater can deliver scalding temperature water at any
faucet in the system. Be careful whenever using hot water to avoid
scalding injury. Certain appliances such as dishwashers and
automatic clothes washers may require increased temperature
water. By setting the thermostat on this water heater to obtain
the increased temperature water required by these appliances,
you may create the potential for scald injury. To protect against
injury, you should install a mixing valve in the water system.
This valve will reduce point of discharge temperature by mixing
cold and hot water in branch supply lines. Such valves are
available from the local plumbing supplier.
Figure 6-3 Scald Warning Label Located on the Appliance
The following chart (Table 6B) 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.
Table 6B Approximate Time / Temperature Scald Chart
APPROXIMATE TIME / TEMPERATURE
RELATIONSHIPS IN SCALDS
120°F
125°F
130°F
135°F
140°F
145°F
150°F
155°F

Water chemistry

Water temperature rise and maximum
NOTICE
flow data is based on heating potable
water with a hardness of 5 to 25 grains
per gallon and total dissolved solids
not exceeding 350 ppm.
The required temperature rise and the standard
circulating pump are sized based on the heating of
potable water with a hardness of 5 to 25 grains per gallon
and a total dissolved solids not exceeding 350 ppm.
Consult the manufacturer when heating potable water
exceeding these specifications.
Heating of high hardness and/or high total dissolved
solids water may require a larger circulating pump, and a
revised temperature rise specification based on the water
chemistry of the water to be heated.
38
More than 5 minutes
1 1/2 to 2 minutes
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1 1/2 seconds
About 1 second
Table 6C Water Heater Pump Applications / Recommended
Temperature Rise
Model
151
200
286
400
501
601
701
801
Installation & Operation Manual
Water with a hardness of less than 5 grains per gallon will
usually have a pH which can be aggressive and corrosive causing
non-warrantable damage to the pump, and associated piping.
Corrosion due to water chemistry generally shows up first in
the hot water system because heated water increases the rate of
corrosive chemical reactions.

Piping components

Water heater system piping:
Water heater system piping MUST be sized per the pipe
requirements listed in Table 6C. Reducing the pipe size
can restrict the flow rate through the water heater, causing
inadvertent high limit shutdowns and poor system performance.
Check valves:
Field supplied. Check valves are recommended for installation
as shown in FIG.'s 6-4 thru 6-8.
Water heater isolation valves:
Field supplied. Full port ball valves are required. Failure to use
full port ball valves could result in a restricted flow rate through
the water heater.
Anti-scald mixing valve:
Field supplied. An anti-scald mixing valve is recommended
when storing domestic hot water above 115°F.
Unions:
Field supplied. Recommended for unit serviceability.
Temperature and pressure relief valve:
Factory supplied on water heaters. The temperature and pressure
relief valve is sized to ASME specifications. Storage tanks may
require additional valves depending on local codes.
Tank sensor:
Lochinvar supplies a tank sensor. The tank sensor must be
installed in the tapping provided in the lower 25% of the storage
tank to achieve proper operation. As shipped from the factory,
the tank sensor is in the literature package shipped with the unit.
Placing the sensor in the tapping provided on the storage tank
will improve temperature response and prevent short cycles of
operation.
Water Heater Pump Applications
*Pipe
Armstrong Grundfos
Size
1-1/4" E8 --
1-1/4" E8 --
2" E17 --
2" E24 --
2" E22 --
2" E22 --
2" -- TP 40-160
2" -- TP 40-160
Pump sizing and flow requirements are based on 45 feet of
NOTICE
piping, 4 - 90° elbows, and 2 - fully ported ball valves.
Flow Rate Loss Temp.
(GPM) (FT/HD) Rise
16 16.6 18°F
21 11.8 18°F
30 17.1 18°F
39 21 18°F
53 26 18°F
53 26 22°F
63 32 22°F
67 31 24°F