A.O. Smith Burkay HW-300 Installation Operation & Maintenance page 36

TWO HW-399's, HW-420's, HW-520's, HW-610's or HW-670's UP-FLOW MODEL
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.
WIRING - FIGURES 20, 21, 22, OR 23
HEATERS SPACED 30" APART
INSTALL IN ACCORDANCE
WITH ALL LOCAL CODES
USE THIS TABLE FOR CORRECT
PUMP AND WATER PIPE SIZE
MinimumPipe Size
Model
Number A
HW-300 2"
HW-399 2"
HW-420 2"
HW-520 2"
HW-610/670 2-1/2"
*Assumes 50 equivalent feet pf piping or less.
COMMERCIAL BOILER WITH VERTICAL TANK, CER-TEMP 80
DANGER
B & G *Armstrong
(Inches) Pump
B Size
1-1/2" 2"
1-1/2" 2"
1-1/2" 2"
1-1/2" 2"
1-1/2" 2-1/2" S-45 2-1/2"
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.
Pump
Size
S-35
S-35
S-35
S-35
FIGURE 31
36 36 36 36 36