Raypak 266A - Manual (Page 20)

20
GAS PRESSURE REGULATOR
The gas pressure regulator is preset at 4.0 in. WC
throughout for natural gas, and 10.5 in. WC. for
propane gas. The pressure at the gas valve, taken
with a manometer, should be about 4.0 in. WC natural
gas (3.0 in. WC for Low NOx) and 10.5 in. WC
propane gas. If an adjustment is needed, remove seal
and turn adjustment screw clockwise to increase
pressure or counter-clockwise to decrease pres-
sure.
NOTE: Low NOx gas valves are non-adjustable; set-
ting was made at the manufacturer
(Invensys/Robertshaw).
GAS PRESSURE ADJUSTMENT LOCATIONS
MILLIVOLT GAS VALVES
ELECTRONIC IGNITION GAS VALVES
Gas Pressure
Adjustment
Gas Pressure
Adjustment
Fig # 9263
Fig # 9263
Robertshaw 7000
(Heater Models 206-406)
Honeywell VR8304
(Heater Models 206-
406)
ELECTRONIC IGNITION GAS VALVES-CONTINUED
Gas Pressure
Adjustment
Robertshaw 7200
(Heater Model 206)
Robertshaw 7000 BDER
(Heater Models 266-336)
Gas Pressure
Adjustment
Robertshaw 7000 DERHC
(Heater Model 406)
PIPE SIZING FOR GAS CONNECTIONS
Robertshaw 7000 BDERF
(Heater Models 207-407)
Non-Adjustable
Gas Valve
Maximum Equivalent Pipe Length
Natural Gas 1000 BTU/FT 3 0.60
Specific Gravity @ 0.5 in. WC Pressure Drop
Propane Gas 2500 BTU/FT 3 1.53
Specific Gravity @ 0.5 in. WC Pressure Drop
Input 3/4” 1” 1-1/4” 1-1/2”
Model (KBTU) N P N P N P N P
206/207 199.5 25 60 90 215 360
266/267 266.0 15 35 50 125 210 480 445
336/337 332.5 10 20 30 80 140 320 290
406/407 399.0 15 20 55 95 225 215 480
MANOMETER
GAS PRESSURE
TEST AT GAS VALVE
MANUAL
SHUT-OFF
VALVE