Nilfisk-ALTO 91WS - Manual (Page 33)

1-32 American-Lincoln
91 WS
LP GAS COMPONENTS
FUELLOCK/FILTER
TANK RELIEF VALVE
TANK VALVE
LPG FUEL TANK
PRESSURE RELIEF VALVE
REGULATOR/VAPORIZER
CARBURETOR
P4502B FIGURE 21
LP GAS SYSTEM
The propane powered Model 91WS fuel system has been modified to operate on LP vapor fuel instead of gas.
The LP fuel system consists of several components not found in a regular gasoline system. The LP fuel system
also contains the associated mounting hardware and plumbing for the LP components. The major components
are as follows:
-An LP carburetor
-A combination water-heated vaporizer and regulator
-A combination LP fuel line filter and lock-off valve
-An LP fuel tank, fittings, and relief valves
These components are factory set. Attempts at adjusting these components should only be made by autho-
rized service personnel.
LP VAPOR WITHDRAWAL SYSTEM
The liquid LP fuel flows from the LP tank under its own pressure to the pressure relief valve. This valve is
normally closed, which prevents LP fuel from escaping into the atmosphere. This LP gas is then piped to the LP
fuel filter lock. The fuel filter lock removes unwanted tank scale and deposits from the LP gas. This gaseous LP
fuel is sent to the primary regulator. The primary regulator reduces the pressure of the LP fuel tank and makes
the floe more constant. The secondary regulator reduces LP gas pressure to the level required by the carbure-
tor. From the secondary regulator, the LP fuel is piped to the carburetor where it is finally metered into the air
flow which is sent to the combustion chamber.