Troubleshooting - Johnson Controls VG8000H Handbuch

121 4734 050 E
Causes and remedies when malfunction occurs
When experiencing malfunction please check that the installation and adjustments were carried out in accordance
with these operating instructions. Properly qualified personnel (see: Qualified personnel) must always be present
during maintenance or repair. The TRB 700 is to be observed.
Information about material, temperature and flow direction are to be checked. The conditions of usage must also
correspond to these operating instructions, the data sheet and the technical information given on the ID plate.
Danger

Troubleshooting

Malfunction
No flow
Low flow
Valve stem moves jerkily
Valve stem / plug is stuck
Leakage at stem
Leakage rate is too high when
valve is closed
Valve stem "knocks"
During troubleshooting, safety regulations must be observed unconditionally. If the
problem cannot be solved using the following troubleshooting table please contact the
supplier/manufacturer.
See paragraphs: "Valve Removal" and "Commissioning" for any work to be carried
out on the valve.
Possible Cause
Valve closed
Flange covers were not removed
Valve not sufficiently open
Dirty filters
Blocked pipes
Incorrect valve/k -coefficient selected
vs
Valve plug etched by sticking dirt particles
Very dirty seat and plug
Valve plug is jammed in the seat or guide,
due to deposits or solid particles in the fluid
Valve plug is jammed in the guide, due to
build-up of corrosion behind the stainless
steel seat edge
Stem seal leaking
Sealing surfaces of the seat edge or plug
are washed away or worn
Sealing edge on seat is damaged or worn
Seat and plug are dirty
Actuator thrust too low
Flow-through valve in wrong direction
Remedial Action
Open valve (using actuator)
Remove flange covers
Open valve (using actuator)
Clean or replace filters
Only when system is free of
pressure!
Check piping system
Replace valve with valve of greater
k -coefficient
vs
Clean internal parts, smooth
damaged areas
Clean seat and plug with appropriate
cleaning agent
Replace plug, clean seat
VDI 2035 directive must be
observed! Use valve with special
internal coating
Replace packing
Observe by-pack instructions!
Replace plug (when necessary with
stem) and/or seat ring
Replace valve
Clean valve internal parts
Use actuator with more thrust
Correct the flow direction
17 E