Delta F-25 Electric Heater User Manual


 
11
Domestic Piping
SECTION IV - Domestic Piping
General Piping Requirements
All plumbing must meet or exceed all
local, state and national plumbing codes.
Use pipe dope or tape suitable for
potable water.
Use isolation valves to isolate system
components.
Install unions for easy removal of the
ELITE from the system piping.
Domestic Supply Pressure
For applications in which the domestic sup-
ply pressure exceeds 70 psig it is recom-
mended to install a pressure reducing valve
on the cold water supply.
Maintaining the cold water supply at or
below 70 psig will prevent normal thermal
expansion from repeatedly forcing the T&P
relief valve open.
Thermal Expansion
If the cold water supply contains a backflow
preventer, check valve and / or a pressure
reducing valve, the installer must install a
domestic thermal expansion tank on the cold
water supply. (See Fig. 2 page 14)
Installing a thermal expansion tank will
prevent normal thermal expansion from
repeatedly forcing the T&P relief valve
open.
When installing a thermal expansion tank
ensure the charge pressure of the tank is
equal to the cold water supply pressure at
the point of installation. Consult the ther-
mal expansion tank manufacturer’s instruc-
tions for further information on installation
and sizing.
The Temperature / Pressure relief valve
is not intended for constant duty, such as
relief of pressure due to normal thermal
expansion.
Water Hammer
Water hammer is the effect of sudden pres-
sure changes occurring in the domestic pip-
ing. These pressure changes are typically
the result of “fast acting” positive shut-off
valves closing. These types of valves can
be typically found on dishwashers and
clothes washers.
The effects of water hammering can cause
damage to system components and tank
welds on the unit.
Installation of hammer arresters is recom-
mended at these types of appliances, which
incorporate “fast-acting” positive shut-off
valves. Consult the manufacturer of water
hammer arresters for recommendation on
sizing and installation requirements.
Temperature / Pressure Relief Valve
The ELITE has a factory installed
Temperature / Pressure Relief valve.
Ensure the rating of the T&P relief valve is
correctly sized as follows per AGA:
CAUTION
Model AGA Rating
F-25 100,000 Btu/hr
F-30 200,000 Btu/hr
F-35 200,000 Btu/hr
F-40 200,000 Btu/hr
F-45 200,000 Btu/hr