P-K SONIC
®
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: June 2, 2017
Released: June 2, 2017
HARSCO Industrial, Patterson-Kelley 2017
All Rights Reserved.
1004905978 P-K SONIC NURO Installation and
Owners Manual (Rev F Jun-2017).docx
Page 37
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.
Heat
Exchanger
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 SC-1500, SC-2000, SC-3000, and SC-4000 boilers require an ASME Section IV relief valve to be
installed on the top of the OUTLET (Supply) connection. The spindle of the relief valve must be vertical.
The ASME Section IV relief valves are available for purchase from Harsco Industrial, Patterson-Kelley.
The SC-3000 and SC-4000 boilers also require an ASME Section VIII relief valve to be installed somewhere
on the boiler or connecting piping before any isolation valve(s). A side port on the OUTLET (Supply)
connection is available for this purpose. The ASME Section VIII relief valve is provided with the SC-3000
and SC-4000 boilers for convenience.
Low Water Cut-Off
The boiler is furnished with a probe-type low water cut-off; no field piping is required. If the water level in
the boiler drops below the probe, the boiler will shut down and LOCKOUT LOW WATER LEVEL will be
displayed on the control panel. The low water cutoff circuit will automatically reset
when the low water
condition clears; however the boiler controls will retain the lockout condition until the reset button on the
display is depressed. Installation of external limit controls may be required by certain codes or in certain
installations. Review applicable local codes for details
.
Drain Valve and Piping
The P-K SONIC
®
boilers feature a ¾” drain connection. Prior to draining the boiler, electrical power and
gas supply must be turned off to the boiler, and the boiler must be isolated from the system at the supply
and return connections
.
NOTICE!
Some local jurisdictions may require an auxiliary low water cut-off device installed in the
external piping. The auxiliary low water cutoff device only prevents operation when the water level
in the appliance is insufficient. It does not detect low water conditions in other parts of the system.
Installation o
f automatic air vents in the “high points” of the piping or additional low water safety
devices should be considered to protect the system.
NOTICE!
The 3/4” manual drain is for draining the water inside the heat exchanger only, not the
entire hydronic or
domestic system. Draining the entire system through the boiler or water heater’s
drain valve will deposit sediment and debris from the system inside the heat exchanger. This will
result in poor heat transfer and premature failure. Refer to
for more information on best piping practices.
N
OTICE
!
Heat exchangers have a minimum water pressure of 14.5 psi.
