Burkert 2712 Instructions De Service page 46

Replacement of the control cone
On the fluidic side it is possible to exchange the control cone if it becomes worn or damaged. For this purpose the drive unit must
be disassembled from the housing.
Disassembly:
Remove the electrical and pneumatic supplies from the TopControl.
Pull off the control cone with the aid of two metal strips of equal height that are clamped to the left and right of the spindle
between the control cone and the threaded nipple of the drive unit. To pull off the control cone, apply compressed air (approx.
6 bar) to the lower control connection of the drive.
Pull off the pneumatic hose between TopControl and drive unit at control connection of drive unit.
In the case of control function A, pressurize the lower control connection of the drive unit with compressed air (5 to 7 bar) so
that the control cone lifts from the valve seat and is not damaged. With control function B, no compressed air must be applied
for this purpose.
Remove the drive unit in the open valve position by unscrewing the threaded nipple of the housing.
Before reinstalling the drive (in open valve position), grease the nipple thread with stainless steel lubricant, e.g. silicone
grease CKS 1110 from OKS, Munich and replace the graphite seal.
Control cone
Dowel pin
Type 2712
M
AINTENANCE AND
Replacement of control cone:
Knock out the dowel pin with a suitable driver.
Driver diameter:
φ 4 mm
up to DN 25
φ 5 mm
up to DN 32
Push the new control cone over the end of the spindle.
Align the bores.
Support the control cone at its cylindrical part with the aid of a V-
block or the like.
Carefully knock the dowel pin into the bore with a hammer.
Bring the dowel pin into a central position relative to the spindle axis
(knock in as far as the end of the recess).
ATTENTION!
Do not damage the sealing surface or the
control contour!
S V
ERVICING OF THE ALVE
MS 3