Schwank P40U Fenwal - Manual (Page 22)

22
P40U-F / P40U-IF I&O Manual
IM101220
RD: MAY 2014
RL: 5A
DO NOT use pressure greater than 1/2 psig to pressure check the heater. During
any pressure testing of the gas piping system each heater must be isolated from
the piping system by closing its individual manual shut off valve (field supplied) .
IMPORTANT: Minimum supply line pressure at the inlet to the heater regula-
tor must not be lower than 5.0 inches of water column pressure for natural gas. 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.
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
ORIENTATION OF FLEXIBLE GAS CONNECTOR
The flexible gas connector MUST be installed in the orientation shown below as required by
national installation codes and by the certification standard of this heater. This orientation pro-
tects the flexible gas connector from damage due to movement during heater expansion.
It is the responsibility of the installer to ensure correct installation of the flexible gas connector.
FIGURE 12
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.
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