Gas Supply Connections; Supply Pressures; Gas Pressure Adjustment Locations; Pipe Sizing For Gas Connections - Rheem Raypak X94 Professional SR-410 Manuel D'installation Et D'utilisation

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.
MUST BE INSTALLED
BY INSTALLER
GAS INLET
3" MIN
UNION
(7.6 cm)
SEDIMENT
TRAP
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 CO2 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.
20
MANUAL
WRENCHING
BALL
NIPPLE
VALVE
3/4 NPT
REAR
JACKET
F10329

Gas Pressure Adjustment Locations

ADJUSTING SCREW
+
= MORE GAS
– = LESS GAS
GAS
INLET
Figure 16. Gas Valve

Pipe Sizing For Gas Connections

Maximum Equivalent Pipe Length, ft. (m)
3/4" 1"
NAT PRO NAT PRO
15 20 55
(4.6) (6.1) (16.8)
*
4.6 6.1 16.8
(1.4) (1.8) (5.1)
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.
Heat Exchanger Pressure
Drop Tables
Heat Exchanger with External Automatic Bypass
WATER FLOW
GPM (lpm)
40 (151)
50 (189)
60 (227)
70 (265)
80 (303)
90 (341)
100 (371)
110 (4161)
120 (4541)
125 (4731)
Table L. Heat Exchanger Pressure Drop
F10330
1-1/4" 1-1/2"
NAT PRO NAT
95 225 215
(29) (68) (65)
29 68.6 65.5
(8.8) (21) (20)
Gas Line Sizing
HEAD LOSS
FT. WC. (kPa)
5.3 (1.32)
5.9 (1.47)
6.2 (1.54)
7.2 (1.79)
8.6 (2.14)
9.7 (2.42)
11.3 (2.81)
13.2 (3.29)
15.3 (3.81)
16.5 (4.11)
PRO
480
(146)
146
(44)