Gas Supply Connections; Supply Pressures; Gas Pressure Adjustment Locations; Pipe Sizing For Gas Connections - Raypak X94 Installation & Operating Instructions Manual

GAS SUPPLY CONNECTIONS

Fig. 13: Gas Supply Connections
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. All gas piping should be
tested after installation in accordance with local codes.
CAUTION: The heater and its manual shut-off 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 shut off valve to gas supply line. FAIL-
URE TO FOLLOW THIS PROCEDURE MAY DAM-
AGE 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 sparing-
ly 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.
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

Fig. 14: Gas Valve

PIPE SIZING FOR GAS CONNECTIONS

Maximum Equivalent Pipe Length (ft)
Natural Gas 1000 BTU/FT
0.60 Specific Gravity @ 0.5 in. WC Pressure Drop
Propane Gas 2500 BTU/FT
1.53 Specific Gravity @ 0.5 in. WC Pressure Drop
Input 3/4"
Model (KBTU) N
410 399.0 *
*A 3/4" gas line can be used for up to 5' (1.52 m) maximum length
from the gas valve in addition to the sediment trap.
** Dimension in meters.
Table 8: Pipe Lengths for Gas Connections

HEAT EXCHANGER PRESSURE DROP TABLES

Heat Exchanger with External Automatic Bypass
WATER FLOW
(GPM)
40 (151.4 LPM)
50 (189.3 LPM)
60 (227.1 LPM)
70 (265 LPM)
80 (302.8 LPM)
90 (340.7 LPM)
100 (378.5 LPM)
110 (416.4 LPM)
120 (454.2 LPM)
125 (473.2 LPM)
Table 9: Heat Exchanger Pressure Drop
26
3
3
1" 1-1/4"
P N P N P
15 20 55 95 225 215 480
4.6 6.1 16.8 29 68.6 65.5
** ** ** ** **
HEAD LOSS
(FT WC)
5.3 (1.32 kPa)
5.9 (1.47 kPa)
6.2 (1.54 kPa)
7.2 (1.79 kPa)
8.6 (2.14 kPa)
9.7 (2.42 kPa)
11.3 (2.81 kPa)
13.2 (3.29 kPa)
15.3 (3.81 kPa)
16.5 (4.11 kPa)
1-1/2"
N P
146
** **