Section Iv - Domestic Piping; General Piping Requirements; Domestic Supply Pressure; Thermal Expansion - Delta Performance PG-25 Installation And Maintenance Manual

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
PERFORMANCE 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 to the domestic
inner tank 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. 6 page 17)
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.
CAUTION
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 PERFORMANCE has a factory
installed Temperature / Pressure Relief
valve. Ensure the rating of the T&P relief
valve is correctly sized as follows per
AGA:
Model
PG-25
PG-30
PG-35
PG-40
PG-45
14
AGA Rating
100,000 Btu/hr
200,000 Btu/hr
200,000 Btu/hr
200,000 Btu/hr
200,000 Btu/hr