Circulator Sizing - Munchkin HIGH EFFICIENCY HEATER with the "925" Controller Operating Instructions Manual

8. Install an Air Elimination Device on the system supply.
9. Install a drain valve at the lowest point of the system. Note: The Munchkin can not be drained
completely of water without purging the unit with an air pressure 15 PSI.
10. The Safety Relief Valve is installed at the factory located on the right hand side of Munchkin.
Pipe the discharge of safety relief valve to prevent injury in the event of pressure relief. Pipe
the discharge to a drain. Provide piping that is the same size as the safety relief valve outlet.
Never block the outlet of safety relief valve.
11. In compliance with ASME CSD-1, a low water cut-off device should be properly connected in
the field, both electrically and mechanically.
See the piping illustrations included in this section, Figs. 5-3 to 5-11 for suggested guidelines in
piping the Munchkin heater with either zone valves or circulator pumps.
*Please note that these illustrations are meant to show system piping concept only, the installer
is responsible for all equipment and detailing required by local codes.
B. CIRCULATOR SIZING
The Munchkin Heat Exchanger does have pressure drop which must be considered in your system
design. Refer to the graph below for pressure drop through the Munchkin Heat Exchanger.
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1
0
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Figure 5-1
* THE RECOMMENDED CIRCULATORS ARE BASED ON 1 GPM PER 10,000 BTU/HR W/20
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Flow in Gallons per Minute
MUNCHKIN T50M
MUNCHKIN 140M
BOILER
T50M/T80M/80M
MUNCHKIN T80M/80M
MUNCHKIN 199M
TACO P/N
007 *
140M 0010 *
199M 0011 *
PIPING
GRUNDFOS P/N
UPS15-58 FC SPD 2
26-64 F
26-96 F
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