Tests And Adjustments; N-2007 Regulator Service Testing - Doosan G424FE Service Manual

Tests and Adjustments

WARNING—PROPER USE
• LP gas is highly flammable. To prevent
personal injury, keep fire and flammable
materials away from the lift truck when work is
done on the fuel system.
• Gas vapor may reduce oxygen available for
breathing, cause headache, nausea, dizziness
and unconsciousness and lead to injury or
death. Always operate the forklift in a well
ventilated area
• Liquid propane may cause freezing of tissue or
frostbite. Avoid direct contact with skin or
tissue; always
protection including gloves and safety glasses
when working with liquid propane.
The regulator/converter and mixer are part of a
certified system complying with EPA and CARB
2007 requirements.
technicians should
service or replacement
converter or mixer.
G424F(FE) Service Manual
wear appropriate
CAUTION
Only trained,
perform disassembly,
of the regulator

N-2007 Regulator Service Testing

For checking
operation, the following tests can be performed (See
Chapter 5 for removal/installation of the N-2007
regulator). To check the secondary regulation
(output) a simple vacuum hand pump can be used
to simulate the vacuum signal transmitted from the
air/fuel mixer when the engine is running. See listing
below for required hardware.
Break-Off Test
Secondary Stage Test Hardware
1. Hand vacuum pump
2. Regulator vapor outlet test fitting 3/4" NPT x 1/4"
hose barb
safety
3. Union Tee 1/4" NPT with three 1/4" NPT x 1/4"
hose barb
4. Vacuum hose
5. 0-3" WC Magnehelic gauge (inches of water
column)
Secondary Stage (Break-Off) Test
certified
1. Connect the vacuum pump, the Magnehelic
gauge and the regulator vapor outlet to the Union
Tee fitting (Figure 34). Make sure there is no
leakage at any of the fittings.
2. Using the vacuum pump slowly apply enough
vacuum to measure above -2" WC on the gauge.
This vacuum signal opens the secondary valve in
the N-2007 regulator/converter.
3. Release the vacuum pump lever and you will see
the gauge needle start falling back toward zero.
When the pressure drops just below the specified
break-off pressure (-0.5 +/- 0.35 " WC) of the
secondary spring, the needle should stop moving.
4. At this point the secondary valve should close. If
the secondary valve seat or the secondary
diaphragm is leaking the gauge needle will
continue to fall toward zero (proportional to the
leak size). An excessively rich air/fuel mixture can
be caused by a secondary valve seat leak and the
regulator should be replaced.
183
the N-2007
Chapter 6. LPG FUEL DELIVERY SYSTEM
regulator/converter