Piping - A.O. Smith HW 300 Installation & Operation Manual

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR ONE HW-670 UP-FLOW MODEL
COMMERCIAL BOILER WITH VERTICAL TANK
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE
INTERRUPTION OR CIRCULATOR FAILURE.
+ PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD
CONFORM TO LOCAL CODES.
GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.
* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.
** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.
Model
Number
HW-300
HW-399
HW-420
HW-520
HW-610/670
* Assumes 50 equivalent feet of piping or less.

PIPING

WIRING - FIGURES 16 and 17 on
pages 24 and 25.
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
Minimum B & G
Pipe Size Pump
(Inches) Size
1-1/4" 125
1-1/2" 1-1/2" HV
1-1/2" 1-1/2" HV
1-1/2" 1-1/2" HV
2" 2"
FIGURE 28.
33
DANGER
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE
TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE
CONTROL WARNING ON PAGE 11. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
*Armstrong
Pump Size
S-25 1-1/4"
H-32 1-1/2"
H-32 1-1/2"
H-32 1-1/2"
S-35