Raypak 500 User Manual
Page 14
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.
14
Table G: Heater Rates of Flow and Pressure Drops
Notes: Basis for minimum flow is ∆T . Basis for maximum flow is gpm.
Fig. 7: Single Heater — Low-Temperature (Heat Pump)
Application with Primary/Secondary Piping
Fig. 8: Dual Heaters (Reverse/Return)
with Primary/Secondary Piping
*Maximum 4 times the pipe diameter or 12”, whichever is less.
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Model
No.
20°F ∆T
30°F ∆T
40°F ∆T
Min. Flow
Max. Flow
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
Fig. 6: Air-Separation/Expansion Tank
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.