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A.O. Smith DB/DW-720-1810 User Manual

Page 29

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29

TWO DURA-MAX (MODEL DW) HOT WATER SUPPLY BOILERS WITH VERTICAL TANK

CAUTION

TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100°F (38°C)

SEE PAGE 31 FOR ADDITIONAL
PIPING INFORMATION.

CAUTION

PUMP MUST BE RATED FOR SYSTEM OPERATING
TEMPERATURE AND PRESSURE

.

*

SAFETY RELIEF VALVE RATING SHOULD NOT EXCEED
PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.

INSTALL IN ACCORDANCE WITH ALL LOCAL CODES.

+ BALL VALVES ARE SHOWN FOR SERVICING BOILER,

HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

ALL PIPING MUST BE SUPPORTED.

IMPORTANT

THE INSTALLATION OF SAFETY FLOW SWITCHES AS
SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE
OF WATER SERVICE INTERRUPTION OR CIRCULATOR
FAILURE.

NOTE: THERMOMETERS, RELIEF VALVES,CIRCULATORS,

SAFETY FLOW SWITCHES AND TANK CONTROLS
ARE AVAILABLE THROUGH A.O.SMITH.

FIGURE 22

Guide To Pipe and Pump Sizing

Two (2) Boiler Systems

Common

Manifold Pipe

Boiler Pipe Size

Model

Size "A" (Min.)

"B" (Min.) and Pump

720, 840

2-1/2"

NPT

See Table 7

960-1810

3"

NPT

Pipe and pump capacities for two (2) boiler systems
based on 100 equivalent feet (30 meters) heater to
tank loop.