Troubleshooting - Johnson Controls VG8000N Anleitung

18 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 stuck
Leakage at stem
Leakage rate is too high
when valve closed
Valve stem "knocking"
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
Valve plug etched by sticking dirt
particles
Very dirty seat and plug
The 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 washed away or worn
Sealing edge on seat worn or damaged
Seat and plug dirty
Actuator thrust too low
Flow through valve in wrong direction
coefficient selected
vs
121 4349 050 E
Remedial action
Open valve (using actuator)
Remove flange covers
Open valve (using actuator)
Clean / replace filters
Only when system is free of
pressure!
Check piping system
Replace valve with valve of greater
k coefficient.
vs
Clean internal parts, smoothen
damaged areas
Clean seat and plug with suitable
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