Burkert 2012 Manuel D'utilisation page 21

Maintenance, Cleaning
→
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
Seat Body Uncoated
seats
DN 4-15 DN 15
DN 20 DN 20
DN 25 DN 25
DN 32 DN 32
DN 40 DN 40
DN 50 DN 50
DN 65 DN 65
DN 80 DN 80
DN 100 DN 100
Tab. 5: Tightening torque for installation of seat
Type 2012
Tolerance
Coated
seats
25 20
35 28
50 40
80 65
100 85
120 120
150 150
180 180
220 220
10 MALFUNCTIONS
Malfunction
Actuator
does not
switch
+3
Valve is not
sealed
+3
+5
+5
+8
+8
+10
+10
+10
Valve is
leaking on
the release
bore
Tab. 6: Malfunctions
Reason
→
Pilot air port Connect lower (CFA,
interchanged CFI) or upper (CFB,
CFI) control air
connection
→
Pilot pressure too low
Observe pressure
specifications on the
Medium pressure too
type label
high
→
Flow direction reversed Observe direction
arrow on the body
→
Dirt between seal and Installing dirt trap
valve seat
→
Seat seal worn Installing new seat
seal
→
Flow direction reversed Observe direction
arrow on the type label
→
Medium pressure too
Observe pressure
high
specifications on the
type label
Pilot pressure too low
→
Packing gland worn Renew packing gland
or replace actuator
english
Remedial action
21