Raypak 0180B - Manual (Page 11)

Systems with multiple zones may require an additional circulator. Consult manufacturers data for valve
pressure drops. When an indirect water heating system is used, it is recommended that a separate circulator be
installed to meet the required flow and pressure drop conditions of the indirect water heater.
We recommend that the make up water from the cold water line have a check valve, gate valve, and feedwater
regulator set at 12 psig. Install unions and gate or ball valves at inlet and outlet connections at the boiler to facilitate
servicing.
The pressure relief valve is mounted on the boiler and must be piped to a drain. We recommend that all high
points be vented and that purge valves be installed. A boiler installed above radiation level must be provided with
a low water cutoff device. See page 21 for wiring hook-up. The boiler, when used in connection with a refrigeration
system, must be installed so the chilled medium is piped in parallel with the boiler with appropriate valves to prevent
the chilled medium from entering the boiler.
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.
A diaphragm expansion tank should be installed in the return line. A typical 8" diameter expansion tank can
be used on the models H-0030, H-0042, and H-0066 and an 11" diameter expansion tank can be used on the
model H-0090, H-0135 and H-1080. Consult tank manufacturer for correct sizing.
TYPICAL PIPING
11
SINGLE ZONE PIPING
Fig.# 8997.1
AIR
SCOOP
AIR
VENT
FEED
VALVE
DIAPHRAGM
EXPANSION TANK
HEATING UNITS
COLD
WATER
INLET
PIPE PRESSURE
RELIEF VALVE
TO DRAIN