Flowserve PMV P4 - Manual (Page 18)

18
13. Maintenance
Pilot valve
To remove the pilot valve for cleaning or inspection, remove the screw 1 and carefully lift
out the complete assembly 2. Gently remove the spool 3 from the block and clean the parts,
using methylate cleaner or similar. Blow the parts dry with compressed air. Install the spool
into the pilot valve housing, place it on a flat surface, then lift it carefully in one end. Before
reaching 20 deg angle the spool should slide by itself.
Should the parts show signs of wear, a new assembly is recommended. Mixing spool valves
and valve bodies may result in very high bleed rates and poor performance. Check the O-
rings, then secure and install the pilot valve assembly into positioner unit, press it towards
the positioner housing wall and secure it with screw 1. Make sure that the leaf spring 4 on the
balance arm 5 is properly fitted in the groove on the spool 6. Check again to insure smooth
operation of the assembly.
To maintain original factory performance specifications, use only spool valve assemblies
supplied by PMV.
3
2
1
6
5
4
When upgrading electronically parts inside a PMV positioner approved for
installation in Hazardous locations special procedures apply, permission from
PMV is required prior to the start of work.
Please contact your local PMV Sales office for information regarding
proper procedures.
www.pmv.nu or [email protected]