Raypak 122-322, Operating And Installation Instructions

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SECTION D: WATER PIPING - GENERAL
The heater should be located so that any water leaks will not cause damage to the adjacent area or structures.
CAUTION: This heater requires forced water circulation when the burner is operating. See Table D-1 for
minimum and maximum flow rates and water pump selection. The pump must be interlocked with the
heater to prevent heater operation without water circulation.
RELIEF VALVE PIPING
WARNING: Pressure relief valve discharge piping must be piped near the floor close to a floor drain to eliminate
the potential of severe burns. Do not pipe to any area where freezing could occur. Refer to local
codes.
HYDROSTATIC TEST
Unlike many other types of heaters, Raypak heaters do not require hydrostatic testing prior to being placed in operation. The
heat exchanger has already been factory-tested and is rated for 160 PSI maximum operating pressure. However, Raypak does
recommend hydrostatically testing the piping connections to the heater and the
rest of the system prior to operation. This is
particularly true for hydronic systems using expensive glycol-based antifreeze. Raypak recommends conducting the hydro-
static test before connecting gas piping or electrical supply.
Leaks must be repaired at once to prevent damage to the heater. NEVER use petroleum-based stop-leak compounds.
1. Connect fill water supply. Fill heater with water (be sure bleed valve is open). When water flows from bleed
valve, shut off water. Close bleed valve. Carefully fill the rest of the system, being sure to eliminate any entrapped air
by using high point vents. Close feed valve. Test at standard operating pressure for at least 24 hours.
2. Make sure constant gauge pressure has been maintained throughout test.
3. Check for leaks. Repair if found.
LOW TEMPERATURE SYSTEM
Heater requires minimum inlet temperature of 105°F. Consult sections E, F for piping details.
TEMPERATURE & PRESSURE GAUGE
The temperature and pressure gauge is factory-mounted in the inlet/outlet header.
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