P-K MACH
®
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: January 3, 2020
Released: January 3, 2020
Patterson-Kelley 2020
All Rights Reserved.
1004905981 P-K MACH C1500H-C4000 Installation and
Owners Manual (Rev F Jan-2020).docx
Page 40
OUTLET (Supply)
INLET (Return)
Install
Section IV
Relief
Valve Here
3.7.5 Boiler Water Piping
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.
3.7.6
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 Patterson-Kelley. The bottom rear connection to the boiler is the
INLET and must be used for the return from the system. The top rear connection to the boiler is the
OUTLET and must be connected as the supply to the system. All water piping must be installed such that
no stresses are transmitted to the boiler. The boiler
shall not
be used as a pipe anchor
.
3.7.7 Boiler Water Piping (for Installer)
Strainer
To avoid possible contamination of the boiler with dirt, rust, or sediment from the system, a strainer
near the boiler inlet is strongly recommended. Even new systems may contain sufficient foreign
material to eventually reduce the performance of the heat exchanger. Adequate circulation of good
clean water is essential for maximum efficiency and long life of the boiler. Refer to
Practices For New & Retrofit Systems
for more information on best piping practices.
Relief Valve Piping
Each boiler is supplied with a pressure-relief valve sized in accordance with ASME requirements. The
relief valve discharge must be piped to an acceptable drain at a safe point of discharge. Reducing
couplings or other restrictions are not permitted in the discharge line.
The C-1500H, C-2000H, C-2500, C-3000, and C-4000 boilers require an ASME Section IV relief valve to be
installed on the dedicated safety relief valve connection. The spindle of the relief valve must be vertical.
The ASME Section IV relief valves are available for purchase from Patterson-Kelley.
N
OTICE
!
The C-1500H & C-2000H boilers
are furnished with 2-
1/2” grooved
connections and Victaulic
couplings.
The C-2500 and C-3000 boilers
are furnished with 3” grooved
connections and Victaulic
couplings.
The C-4000 boiler is furnished with
4” grooved connections and
Victaulic couplings.
These couplings must be used with
the EPDM Victaulic seals.
Isolating valves must be installed
in both the inlet and outlet water
connections.
N
OTICE
!
The Condensate Trap must be
piped to a drain in accordance with
all national, state and local codes.
If installed outdoors and the local
requires freeze protection, it must
be field heat traced.
