Rheem Raypa DELTA 399B Installation And Operation Manual page 19

Gas piping must have a sediment trap ahead of the
heater gas controls, and a manual shut-off valve locat-
ed outside the heater jacket. It is recommended that a
union be installed in the gas supply piping adjacent to
the heater for servicing. A pounds-to-inches 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.
ACAUTION: The heater must be disconnected
from the gas supply during any pressure testing
of the gas supply system at test pressures in ex-
cess of 1/2 psi (3.45 kPa).
Gas Supply Connection
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). Re-
lieve test pressure in the gas supply line prior to recon-
necting the heater and its manual shut-off valve to the
gas supply line. FAILURE TO FOLLOW THIS PRO-
CEDURE MAY DAMAGE THE GAS VALVES. Over
pressurized gas valves are not covered by warranty.
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
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
The heater and its gas connections shall be leak-tested
before placing the appliance in operation. Use soapy
water for leak test. DO NOT use an open flame.
Fig. 14: Gas Supply Connection
ACAUTION: 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
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
19