Watts AERCO Benchmark OMM-0137 - Supply and Return Piping; BMK750 - 1000 Supply and Return Piping; BMK1500 - 5000 N Supply and Return Piping

Benchmark Platinum-Edge [ii]: Installation Manual
SECTION 2 – INSTALLATION
OMM-136_H • GF-210 • 1/6/2021 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 23 of 62
2.6 SUPPLY AND RETURN PIPING
When connecting the hot water outlet and cold-water inlet to building piping, first make sure the
mating surfaces are thoroughly clean. Gaskets of appropriate size for the pipe flange must be
provided in the field.
2.6.1 BMK750 – 1000 Supply and Return Piping
Benchmark 750 and 1000 Boiler utilizes 3” (7.62cm) 150# flanges for the water system supply
and return piping connections. The physical location of the supply and return piping connections
are on the rear of the unit as shown in Figure 2-5a.
Figure 2-5a: BMK750/1000 Supply and Return Locations
2.6.2 BMK1500 – 5000N Supply and Return Piping
Benchmark 1500 – 3000 units have the following inlets and outlets:
• 4” (10.2 cm) 150# flange water INLET (supply) and hot water OUTLET (return) piping.
• One of the following gas inlet pipes:
o 2” (5.08 cm) Natural Gas inlet pipe.
o 1” (2.54 cm) Propane inlet pipe (BMK 1500-2000).
o 2” (5.08 cm) Propane inlet pipe (BMK 2500-3000).
• 8” (20.3 cm) Air Inlet adapter.
Benchmark 4000 and 5000N units have:
• 6” (15.2 CM) 150# flange water INLET (supply) and hot water OUTLET (return) piping.
• One of the following gas inlet pipes:
o 3” (7.62 cm) Natural Gas inlet pipe.
1” NATURAL GAS INLET (SINGLE-
FUEL AND DUAL-FUEL MODELS);
1” PROPANE INLET (SINGLE-FUEL
MODELS)
1/4” ANALYZER
NPT PORT
3” HOT WATER OUTLET
(SUPPLY)
CONDENSATE DRAIN
AIR INLET
3” PRIMARY WATER INLET
COOLER WATER RETURN
DRAIN VALVE
3” SECONDARY WATER INLET
WARMER WATER RETURN
3/4” (1.91cm) PROPANE INLET
(DUAL-FUEL MODELS)
LIFTING
BAR
(Must be
removed)