Rheem Raypak X94 SR-410, Installation And Operation Manual

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20
Gas Supply Connections
Gas piping must have a sediment trap ahead of the heater
gas controls, and a manual shutoff valve located outside
the heater jacket. All gas piping should be tested after
installation in accordance with local codes.
GAS INLET
3" MIN
(7.6 cm)
SEDIMENT
TRAP
UNION
REAR
JACKET
3/4 NPT
WRENCHING
NIPPLE
MANUAL
BALL
VALVE
MUST BE INSTALLED
BY INSTALLER
F10329
Figure 15. Gas Supply Connections
A CAUTION: The heater and its manual shutoff valve
must be disconnected from the gas supply during any
pressure testing of that system at test pressures in
excess of 1/2 psi (3.45 kPa). Dissipate test pressure in
the gas supply line before reconnecting the heater and
its manual shutoff valve to gas supply line. FAILURE
TO FOLLOW THIS PROCEDURE MAY DAMAGE THE
GAS VALVE. OVER-PRESSURIZED GAS VALVES ARE
NOT COVERED BY WARRANTY. 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 open flame.
NOTE: 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.
Supply Pressures
A minimum of 4" WC (1 kPa) and a maximum of 10.5"
WC (2.62 kPa) upstream pressure under load and no-
load conditions must be provided for natural gas. A
minimum of 12" WC (3 kPa) and a maximum of 14" WC
(3.5 kPa) are required for propane gas under load and no-
load conditions, with no more than a 30% pressure drop
between static pressure and full load.
Set actual gas manifold pressure based on CO
2 emissions,
using a flue gas analyzer at time of startup. The factory
manifold pressure settings should be -2.0" ± 0.5" WC (0.5
± 0.12 kPa) at high fire (7500 +/- 50 RPM fan-speed) for
either natural or propane gas.
Gas Pressure Adjustment Locations
ADJUSTING SCREW
+ = MORE GAS
– = LESS GAS
GAS
INLET
F10330
Figure 16. Gas Valve
Pipe Sizing For Gas Connections
Maximum Equivalent Pipe Length, ft. (m)
3/4" 1" 1-1/4" 1-1/2"
NAT PRO NAT PRO NAT PRO NAT PRO
*
15
(4.6)
20
(6.1)
55
(16.8)
95
(29)
225
(68)
215
(65)
480
(146)
4.6
(1.4)
6.1
(1.8)
16.8
(5.1)
29
(8.8)
68.6
(21)
65.5
(20)
146
(44)
Natural Gas 1000 BTU/FT3 0.60 Specific Gravity @ 0.5 in. WC
Pressure Drop.
Propane Gas 2500 BTU/FT3 1.53 Specific Gravity @ 0.5 in. WC
Pressure Drop.
* A 3/4" gas line can be used for up to 5' (1.5 m) maximum length from
the gas valve in addition to the sediment trap.
Table K. Gas Line Sizing
Heat Exchanger Pressure
Drop Tables
Heat Exchanger with External Automatic Bypass
WATER FLOW
GPM (lpm)
HEAD LOSS
FT. WC. (kPa)
40 (151) 5.3 (1.32)
50 (189) 5.9 (1.47)
60 (227) 6.2 (1.54)
70 (265) 7.2 (1.79)
80 (303) 8.6 (2.14)
90 (341) 9.7 (2.42)
100 (371) 11.3 (2.81)
110 (4161) 13.2 (3.29)
120 (4541) 15.3 (3.81)
125 (4731) 16.5 (4.11)
Table L. Heat Exchanger Pressure Drop
APPROVED
UNCONTROLLED DOCUMENT IF PRINTED