Rheem Raypak Delta Limited 399B Installation & Operating Instructions Manual page 19

regulator must be installed to reduce the gas supply
pressure to a maximum of 10.5 in. WC for natural gas
and 13.0 in. WC for propane gas. The regulator should
be placed a minimum distance of 10 times the pipe
diameter up-stream of the heater gas controls. Refer
to Table I for maximum pipe lengths.
Gas Supply Connection
CAUTION: The heater must be disconnected from
the gas supply during any pressure testing of the gas
supply system at test pressures in excess of 1/2 psi
(3.45 kPa).
The heater must be isolated from the gas supply
piping system by closing the manual shut-off valve
during any pressure testing of the gas supply piping
system at test pressures equal to or less than 1/2 psi
(3.45 kPa). Relieve test pressure in the gas supply
line prior to reconnecting the heater and its manual
shut-off valve to the gas supply line. FAILURE TO
FOLLOW THIS PROCEDURE MAY DAMAGE THE
GAS VALVES. Over pressurized gas valves are not
covered by warranty. The heater and its gas connec-
tions shall be leak-tested before placing the appliance
in operation. Use soapy water for leak test. DO NOT
use an open flame.
3/4"
Model
No.
N P
399B 15
499B
649B
749B
899B
989B
1259B
1529B
1799B
1999B
2069B
2339B
Natural gas – 1,000 BTU per ft
Propane gas – 2,500 BTU per ft
APPROVED
1" 1-1/4"
N P N P
25 60 100 260
65 150
45 100
35 80
20 45
3
, .60 specific gravity at 0.5 in. WC pressure drop
3
, 1.53 specific gravity at 0.6 in. WC pressure drop
Table I: Maximum Equivalent Pipe Length
UNCONTROLLED DOCUMENT IF PRINTED
Fig. 14: Gas Supply Connection
CAUTION: Do not use Teflon tape on gas line
pipe thread. A pipe compound rated for use with
natural and propane gases is recommended. Apply
sparingly only on male pipe ends, leaving the two
end threads bare.
1-1/2" 2"
N P N P
250
130 360 500
95 250 340
75 180 260 600
45 110 150 360
120 300
75 180
50 120
40 100
30 80
30 80
20 55
19
2-1/2" 3"
N P N P
400
300
170 325 560
125 250 400
100 225 340
75 175 260
75 175 260
55 135 160 400
4"
N P
600