Harsco Industrial MODU-FIRE FORCED DRAFT N750 Installation & Owner's Manual page 24

3.7.1.2 Piping with Refrigeration Machines
When used with a refrigeration system, the boiler shall be installed so that chilled medium is piped in parallel with
the boiler. Valves should be installed to prevent chilled water from entering the boiler when the system is operat-
ed in the cooling mode.
3.7.1.3 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 au-
tomatic means to prevent gravity circulation of the boiler water during the cooling cycle.
3.7.2 Boiler Water Connections
Relief Valve
Drain
Isolating
Valve
Boiler
Drain
Strainer
Make water connections as the application warrants, or at a minimum, as shown, but always in compliance with
the local requirements.
NOTICE! Pipe unions and isolating valves must be installed in both water connections for ease of
service.
The bottom connection to the boiler is the INLET and must be used for the return from the system.
The top connection to the boiler is the OUTLET and must be connected as the supply to the system.
Piping must be installed such that no piping stresses are transmitted to the boiler. The boiler shall not be used
as a pipe anchor.
MODU-FIRE® Forced Draft Gas-Fired Boiler
Union
Isolating
Valve
Outlet to
System
Isolating
Valve
Inlet from
System
Boiler Water Connections
24