Instructions

21
Malfunctions
Type 2012
→ Attach new valve seat to the installation tool.
→ Grease thread with a lubricant (e.g. Klüber paste UH1 96-402).
→ Place attached valve seat on the body thread and screw on by
hand.
→ Using a torque wrench, tighten to the specified tightening torque
(see “Tab. 5”).
Tightening torque for installation of seat
Screw connection Tightening torques
Tolerance
Seat Body
Uncoated
seats
Coated
seats
DN 4-15 DN 15 25 20 +3
DN 20 DN 20 35 28 +3
DN 25 DN 25 50 40 +5
DN 32 DN 32 80 65 +5
DN 40 DN 40 100 85 +8
DN 50 DN 50 120 120 +8
DN 65 DN 65 150 150 +10
DN 80 DN 80 180 180 +10
DN 100 DN 100 220 220 +10
Tab. 5: Tightening torque for installation of seat
10 MALFUNCTIONS
Malfunction Reason Remedial action
Actuator
does not
switch
Pilot air port
interchanged
→ Connect lower (CFA,
CFI) or upper (CFB,
CFI) control air
connection
Pilot pressure too low
→ Observe pressure
specifications on the
type label
Medium pressure too
high
Flow direction reversed
→ Observe direction
arrow on the body
Valve is not
sealed
Dirt between seal and
valve seat
→ Installing dirt trap
Seat seal worn
→ Installing new seat seal
Flow direction reversed
→ Observe direction
arrow on the type label
Medium pressure too
high
→ Observe pressure
specifications on the
type label
Pilot pressure too low
Valve is
leaking on
the release
bore
Packing gland worn
→ Renew packing gland
or replace actuator
Tab. 6: Malfunctions
english