MACH® Series
Gas-Fired Boiler
Installation
22
C2500 Pressure Drop
0
2
4
6
8
10
12
14
16
18
0
50
100
150
200
250
Flow (GPM)
P
ressu
re D
ro
p
(
ft
H
2O
)
3.7.1.1
Piping with Refrigeration Machines
When installed in a two-pipe system that provides both chilled and hot water, the control system should be configured
so as to limit the time rate of change of temperature at the boiler. Consult your authorized Patterson-Kelley boiler
representative for application guidance.
3.7.1.2
Piping with Air Handling Units
The boiler piping system of a hot water heating boiler
connected to heating coils located in air handling units,
where they may be exposed to refrigerated air
circulation, must be equipped with flow control valves
or other automatic means to prevent gravity circulation
of the boiler water during the cooling cycle.
3.7.2
Boiler Inlet and Outlet Connections
All water connections should be in compliance with
national, state and local code requirements.
Adapters from Victaulic to NPT are available from P-K.
The bottom rear connection to the boiler is the INLET
and must be used for the return from the system.
The top vertical connection to the boiler is the OUTLET
and must be connected as the supply to the system.
C2500 Variable Pumping
40
50
60
70
80
90
100
110
120
130
20
40
60
80
100
Firing Rate (%)
Fl
o
w
Ra
te
(
G
P
M
)
Relief Valve
(Pipe to Drain)
Boiler
Inlet
Water
Boiler
Outlet
Water
Strainer
Boiler Drain Valve
Drain
Condensate Drain
Relief Valve
(Pipe to Drain)
Boiler
Inlet
Water
Boiler
Outlet
Water
Strainer
Boiler Drain Valve
Drain
Condensate Drain
NOTICE!
The boiler is furnished with 3” grooved
connections and Victaulic Style 75 Couplings.
These couplings must be used with the EPDM
Victaulic seals. Isolating valves must be installed
in both water connections.