MACH
®
Gas Fired Boiler
28
3.7.3 Boiler Water Piping by 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.
Relief Valve Piping
Each boiler is supplied with a pressure-relief valve sized in accordance with ASME requirements. The relief valve
must be piped to an acceptable drain. Reducing couplings or other restrictions are not permitted in the discharge line.
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 a LOCKOUT LOW WATER LEVEL will be displayed on the
control panel. The low water cut-off will automatically reset when the low water condition clears; however the boiler
control will retain the lockout condition until the reset button on the display is pressed.
NOTICE! The low water cut-off probe only prevents boiler operation when the water level in the boiler is
insufficient. It does not detect low water conditions in other parts of the system. Installation of high point
vents or additional low water safety devices to protect the system should be considered.
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
A drain valve is factory installed in the boiler inlet (system return) piping. 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! This drain valve is factory installed for draining of the boiler water only, not the entire system.
Draining of the system through the boiler will result in depositing sediment from the system in the boiler
which will result in poor heat transfer characteristics of the boiler and early boiler failure.
Condensate Drain
The condensate is acidic (pH between 3.0 and 5.0) and may be corrosive to some building drain systems. A
condensate neutralization system may be required and is available from Harsco Industrial, Patterson-Kelley.
Disposal of condensate must comply with all state and local codes.
The boiler could generate up to one gallon of condensate per 100,000 BTU input. See table below for typical
condensate loading.
MACH
®
Boiler
Typical Condensate
(Gal/hr)
C750
7.5
C900
9
C1050
10.5