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Bulletin 2531-M9/USA
Contents
Troubleshooting Guide
Warning
Before any circuit connection is broken, be sure to turn off all power and relieve system pressure. Lower all vertical
loads and cylinders, lock any load which could produce pressure and discharge any accumulators. Plug and cap all
lines and openings to prevent contamination from entering the system.
Cleaning and Inspection
1. Proper cleaning is a critical part of preventive maintenance in the use of directional control valves. All parts should
be cleaned with a solvent that is compatible with the system fluid. Compressed air may also work well when
cleaning orifices and passage ways, but proper filtration must be employed to remove water and contamination.
NOTE: Always make sure all parts have been cleaned before reassembling.
2. Inspection
a. Inspect all passage ways for obstructions.
b. Inspect all washers, push pins, plungers and pole faces for signs of wear and/or mushrooming. Inspect all
springs for signs of distortion. Replace parts as necessary.
c. Look for nicks and burrs on the spool and bore lands. Nicks in these areas indicate likely contamination of the
system fluid.
3. If there are no signs of nicks or burrs on the spool and bore, check the spool clearance as follows:
a. Lubricate the spool and bore with clean system fluid.
b. Insert the spool back into the body and slowly move the spool back and forth. The spool should move freely. If
there is any sticking between the spool and the bore, remove the spool and repeat 2b.
c. The spool clearance can also be checked by placing the valve body on end and inserting the spool. Gravity will
pull the spool to the other end if there is no sticking.
d. After several attempts have been made without resolution, replace the valve.
Troubleshooting
Problem: Valve spool fails to move
Cause
Recommended flow exceeded
Recommended pressure exceeded
Improper installation connections
Contamination in system
Improper assembly
Valve has silted
Pilot supply off
Inadequate pilot pressure
Problem: Valve produces undesirable response
Cause
Recommended flow exceeded
Recommended pressure exceeded
Improper installation connections
Contamination in system
Improper assembly
Improper fluid
Recommended temperature exceeded
(indicated by fluid discoloration or spool tarnishing)
Inadequate pilot pressure
2531-M9.pm6, sm, jj
Hydraulics
Directional Control Valves
Series D1VW, B Style
Series D1VA
Recommendation
Check maximum flow rate for appropriate spool by spool function.
Check maximum pressure rating for valve.
Check installation drawings.
Disasemble, inspect, clean and flush.
Check proper assembly. Refer to drawing for appropriate model.
Disassemble and clean valve.
Turn supply on.
Check pilot pressure specifications for valve model.
Check pilot/connections for leak.
Recommendation
Check maximum flow rate for appropriate spool by spool function.
Check maximum pressure rating for valve.
Check installation drawings.
Disassemble, inspect, clean and flush.
Check proper assembly. Refer to drawing for appropriate model.
Check fluid recommendations.
Check maximum temperature recommendations.
Check pilot pressure specifications for valve.
Check pilot/connections for leak.
9
Parker Hannifin Corporation
Hydraulic Valve Division
Elyria, Ohio 44035 USA
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