TROUBLESHOOTING
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General Comments - Paragraph 1 - Exhaust Port Leakage
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Verify if the leakage is caused by the cylinder or valve as follows:
(Use extreme caution, as the valve and cylinder will both be actuated
during this procedure.)
1. With the piston rod retracted, disconnect the line at
the cylinder blind end cap. If air comes out of the cylinder port
fitting, as shown above, the cylinder piston seals are defective
amd must be replaced. If there is no leakage, reconnect the line.
2. With the cylinder rod extended, disconnect the line at the cylinder
rod end cap. If there is leakage at the cylinder port fitting,
the cylinder piston seals must be replaced.
3. If there is no leakage at the fitting, the leakage is caused
by defective valve seals or gaskets. Reconnect the line and install
new seals and gaskets that are included in the valve body service
kit.
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General Comments - Paragraph 2 - Inadequate Air Supply
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An inadequate air supply can cause the pilot supply
pressure to drop during valve actuation. This can result
in valve chatter or oscillation, particularly in poppet
valves, or may keep the valve in a partially shifted
condition where it continually blows to exhaust. If the
pressure gage falls by more than 10% during valve actuation,
there is probably a deficiency in the air supply system.
1. Airline filters should be cleaned and pressure
regulators checked for proper operation. The line sizing
recom-mendations
in the “Installation” section of this catalog should be reviewed
and modifications made if restric-tions or undersize inlet lines
are found.
2. Verify that the air compressor has sufficient capacity to meet
all systems requirements.
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General Comments - Paragraph 3 - Pilot Supply
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Remote air pilot signals or pilot supplies to externally
piloted solenoid valves that are restricted or are below
the minimum operating pressures given in this catalog
can cause valve oscillation or partial actuation resulting
in ex-haust port leakage.
1. Verify that the operating signal is at the proper pressure
and that there are no restrictions caused by clogged filter elements
or improperly sized pilot lines.
2. Comments in Paragraph 2 also apply to pilot supplies.
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General Comments - Paragraph 4 - Liquid Contamination
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Accumulation of oil and water at low points in
the system, including valves, can cause erratic or sluggish
perfor-mance and exhaust leaks.
1. If heavy concentrations of water or oil are found when
a device is disassembled, it should be thoroughly cleaned, re-lubricated
and reassembled.
2. Filters and lubricators should be cleaned and checked for proper
operation. If necessary, air lines should be rerouted to eliminate
low points.
3. If there are concentrations of moisture at below freezing temperatures,
ice can form and cause erratic operations, or completely bind system
components. In such situations, steps must be taken to dry the
air to a dew point of at least 10 o F below the minimum system
operating temperature. Also, filters should be equipped with automatic
drains.
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General Comments - Paragraph 5 - Solid Contamination
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Solid contaminants, such as broken pieces of pipe
threads, pipe sealant or tape, or rust scale, can cause
valve seal damage, scratches on spools and sealing surfaces,
or system binding and possible exhaust leaks. Such problems
ar most often encountered in new installations that have
not been properly purged or where there are heavy concen-trations
of atmospheric contaminants.
1. In may cases, cycling the valve several times will flush
the particles away. If not, the item must be disassembled, the
parts thoroughly examined for signs of damage and replaced as necessary.
2. Before reinstalling the product, the air line should be purged,
as stated in the “Installation” section of this catalog. Air line
filters should be cleaned and checked for proper operation. Properly
sized mufflers should be installed in valve exhaust ports.
3. If there is heavy atmosphere contamination, valves with foundry
option “D” should be installed.
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41144
Vincenti Ct 
PROFILE