A.O. Smith 505 Series 100 用户手册

Drawing Number:

Drawing Date:

September 07, 2008

NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro-
fessional engineering drawing. It is intended only as a guide and does not imply compliance with local 
building code requirements. Confer with local building officials before installation

. The Contractor or 

engineer is to determine the necessary components and configuration of the particular system to be in-
stalled. It is the responsibility of the engineer or contractor to ensure that the installation is in accordance 
with all local building codes.

29

On-Demand
Equipment List 

QTY

On-Demand 

        6

Water Heaters

Domestic Hot Water - Circulation Systems

6 On-Demand Water Heaters with Gas or Electric Tank

Preferred Piping Installation

Pump should be controlled by an Aquastat, 
Timer or Combination Aquastat and Timer.

Pump to be sized to maintain circulation 
loop temperature.

The pump should be sized to overcome the 
pressure loss through the tank water heater, 
and supply and return plumbing in the 
circulation loop.  Reference the section 
Pump Sizing for Circulation.

Pump to be of bronze or stainless construc-
tion.

Electronic Connection *

* Refer to On-Demand Accessories 
  and Model Applicability for 
  electronic connection details.

Cold Water Supply Line

Gas Supply

Hot Water
Supply Line

Smaller Return Line 
Can Be Used After 
The Last Fixture

Expansion Tank

(Optional) Header Sized One Pipe Size Larger Than Hot 
Water Supply Line - (

To eliminate cold water sandwich effect 

caused by frequent On/Off operation)  

Gas or Electric 

Tank Water 

Heater

Pressure
Regulator Set to 
5 PSI Below 
Street Pressure

Building Outlets

Aquastat Connection

Tank  Water
Heater sized
to  maintain
circulation loop
temperature

Key

Pressure Relief  Valve

Check Valve

3/4" Union

3/4" Ball  Valve

Boiler Drain Valve

Solenoid Valve

S

Pressure Regulator

Circulating Pump

Mixing Valve