Lochinvar Power-Fin Designer's Manual page 22

Designer's Guide / Power-fin Water Heater
The list below shows the gas connection size on the water heater. Logically, the gas pipe size
from the meter to the water heater may be larger than the appliance connection.
The table below lists the Minimum and Maximum Inlet Gas Pressures. Note how the B9, F9 and
M9 models have different requirements.
Model
Number
PFN0502 – 1302PM
PFN0502 – 1302PM
PFN1501 – 2001PM
PFN1501 – 2001PM
L.P. GAS MODELS
If you are specifying a model for connection to L.P. gas, make sure that is noted on your design
specification. Example, the model number changes from PFN0502PM-M9 to PFL0502PM-M9
from natural to L.P. gas. The Power-fin must be factory trimmed for the chosen gas type and
may not be field converted from Natural to L.P. gas or vice versa.
GAS PRESSURE REGULATORS
Lochinvar recommends the use of "Lock-Up Type" gas pressure regulators on the system gas
supply. A Lock-Up Type gas pressure regulator features a seat that seals the regulator orifice
when the appliance is off and there is no demand for gas. The seat will seal against the orifice
shutting off the flow of gas to the appliance.
A standard regulator without a Lock-Up mechanism will allow the system pressure to reach the
boiler when it is off. The system pressure can "creep up" pressing against the appliance gas train
with excessive system pressures. This can damage the components in the gas train.
Important
HIGH PRESSURE GAS REGULATORS MUST BE THE LOCK-UP VARIETY AND MUST BE INSTALLED NOT
LESS THAN 10 EQUIVALENT FEET FROM THE BOILER TO PROVIDE AN ADEQUATE VOLUME OF GAS
FOR SMOOTH IGNITION.
MODEL PIPE SIZE
1"
PFN0502PM
PFN0752PM 1-1/4"
PFN1002PM 1-1/4"
PFN1302PM 1-1/4"
INLET GAS PRESSURE
Firing NATURAL GAS
Code Max. w.c.
F9 10.5
M9 14.0
B9 14.0
M9 14.0
MODEL PIPE SIZE
PFN1501PM 2"
PFN1701PM 2"
PFN2001PM 2"
L.P. GAS
Min. w.c. Max. w.c.
4.2 13.0
4.0 13.0
4.0 14.0
4.0 14.0
22
LOCHINVAR CORPORATION
300 MADDOX SIMPSON PKWY
LEBANON, TN 37090
www.lochinvar.com
Min. w.c.
11.0
11.0
8.0
8.0