Raypak 090A - Manual (Page 12)

12
Gas Pressure Specifications
Gas Pressure Regulator
The gas valve is provided with pressure taps to meas-
ure gas pressure upstream of the gas valve and
downstream which is the same as the manifold pres-
sure.
Type of
Gas
Inches WC
Regulator
Setting
Min. Max.*
Natural 4.5 10.5 3.5
Propane 12.0 13.0 11.0
*Do not exceed maximum inlet gas pressure. The minimum value
shown is for input adjustment.
Table G: Gas Pressure Specifications
Water Connections & System
Piping
The pipe size and fittings between the heater and the
tank should be at least 1" for model 90, and 1-1/4" for
models 135 and 195. This is based on the tank being
located as close to the heater as possible, as shown in
Fig. 7 below.
If this water heater is installed in a closed water supply
system, such as one having a back-flow preventer in
the cold water supply line, means shall be provided to
control thermal expansion. Contact the water heater
supplier or local plumbing inspector on how to control
this situation.
Hot Water Supply
Thermometer
Cold Water
Recirculation Water
Check Valve
Thermostat
Pressure Relief Valve
T & P Relief Valve
Pump
Install Temperature &
Pressure Gauge in the
Outlet Water Connection
Fig. 7: Heater with Storage Tank