Raypak 850, 300 Air-Separation/ExpansionTank, Three-WayValves, Domestic Hot Water

Air-Separation/Expansion Tank

Fig. 6: Air-Separation/Expansion Tank

All heaters should be equipped with a properly sized expansion tank and air separator fitting as shown in Fig. 6 above.

Three-Way Valves

Three-way valves intended to regulate system water temperatures by reducing flow in the boiler should not be used. Raypak heaters are high-recovery, low-mass heaters which are not subject to thermal shock.

*Maximum 4 times the pipe diameter or 12”, whichever is less.

Fig. 7: Single Heater — Low-Temperature (Heat Pump)

Application with Primary/Secondary Piping

*Maximum 4 times the pipe diameter or 12”, whichever is less.

Fig. 8: Dual Heaters (Reverse/Return)

with Primary/Secondary Piping

Domestic Hot Water

When designing the water piping system for domestic hot water applications, water hardness should be con- sidered. Table H indicates the suggested flow rates for soft and medium water. Hard water must be softened for direct heating with the XFyre. Water hardness is expressed in grains per gallon.

Model	20°F ∆T		30°F ∆T		40°F ∆T			Min. Flow			Max. Flow
No.	gpm	∆P (ft)	gpm	∆P (ft)	gpm	∆P (ft)	gpm		∆P (ft)	∆T	gpm	∆P (ft)	∆T
300	28	17	19	8	14	5	14		5	40	36	27	17
500	47	16	31	7	24	4	24		4	40	56	24	18
850	80	40	53	17	40	10	40		10	40	80	40	20
Notes: Basis	for minimum flow is		∆T . Basis	for maximum	flow is	gpm.
			Table G: Heater Rates of Flow and Pressure Drops

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