25
P40-R I&O Manual
IM120801
RD: AUG 2013
RL: 1D
TABLE 4
GAS TYPE
LINE PRESSURE
INCHES WATER COLUMN
MANIFOLD PRESSURE
(tap at gas valve outlet)
INCHES WATER COLUMN
MINIMUM
MAXIMUM
Natural Gas
5.0
14.0
3.5
LP Gas
11.0
14.0
10.0
NOTE:
Access to the manifold pressure test port is located on the top of the valve. A 3/16" Al-
len Key is required. A
manometer
should be used to check the manifold pressure. Gauges
which measure in ounces or PSI are not accurate enough to measure or set the pressure.
GAS CONNECTION
Connection between the gas supply pip-
ing and the appliance must be in accor-
dance with local and national codes,
ANSI Z223.1 (NFPA 54)
in the USA, and
the
CSA B149.1 Natural Gas and Pro-
pane Installation Code
in Canada.
The P40-R is approved as a Vented
Overhead Heater and may be rigid piped
to the building gas supply (
also see
Flexible Gas Connection Option, next
page
).
13.
GAS SUPPLY - GAS CONNECTION … continued
Provide a 1/8 in (3.2 mm) NPT plugged tapping, accessible for test gauge con-
nection, immediately upstream of the gas supply connection to the heater.
The gas supply should be checked first with heater turned “OFF” followed by an-
other check with heater turned “ON”.
This appliance and its main gas valve must be disconnected from the gas supply
piping system during any pressure testing of the gas supply piping system at test
pressure in excess of 1/2 psi (3.5 kPa).
This appliance must be isolated from the piping system by closing the equipment
shut off valve (field supplied) during any pressure testing of the gas piping sys-
tem at test pressure equal to or less than 1/2 psi (3.5 kPa).
I
MPORTANT: Minimum supply line pressure at the inlet to the heater regulator must not
be lower than 5.0 inches of water column pressure for natural gas, and not be lower
than 10.0 inches of water column pressure for LPG. The supply gas pressure must be
checked with all heaters in operation.
Installation of a gas line (trap) “drip leg” is required at the inlet connection tee following the
pipe drop to the heater. Failure to provide a “drip leg” could result in condensation and foreign
matter passing into the gas valve. Failure to install a “drip leg” in the gas line can cause prop-
erty damage, injury or death and will void the heater warranty.
