A.O. Smith Burkay HW-300 Installation Operation & Maintenance page 37

TWO HW-300's, HW-399's, HW-420's, HW-520's, HW-610's OR HW-670's UP-FLOW MODEL
IMPORTANT
THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS
REQUIRED TO PROTECT THE BOILER IN CASE OF WATER
SERVICE INTERRUPTION OR CIRCULATOR FAILURE
(A.O. SMITH PKG. NO.211480).
+ 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.
WIRING - FIGURES 20, 21, 22 or 23
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
COMMERCIAL BOILER WITH HORIZONTAL TANK
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT
FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF
HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO
FIXTURES.
*Assumes 50 equivalent feet pf piping or less.
FIGURE 32
37 37 37 37 37
DANGER
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
MinimumPipe Size
Model (Inches)
Number A
HW-300 2" 1-1/2"
HW-399 2" 1-1/2"
HW-420 2" 1-1/2"
HW-520 2" 1-1/2"
HW-610/670 2-1/2" 1-1/2"
B & G *Armstrong
Pump Pump
B Size Size
2" S-35
2" S-35
2" S-35
2" S-35
2-1/2" S-45 2-1/2"