Installation, Operation and Maintenance Manual
MAN-02-05-62-0742-EN Rev. 0
December 2019
Adjusting the Valve Disc
Section 5:
Adjusting the Valve Disc
This instruction is applicable in connection with the mounting of actuators on butterfly
valves with vulcanized rubber.
Guiding Dimensions and Criteria
The disc is adjusted according to the following guiding dimensions:
Figure 8
If possible, the guiding dimension "a" shall be observed, but a deviation of +0 to -25 % can
be accepted.
5.1
Adjustment Procedure
The adjustment criteria for the valve disc can be found in the “Guiding Dimensions
and Criteria”.
1.
The actuator is mounted on the valve, so that the indicator groove follows the disc.
The nut/counter-nut is loosely tightened.
2.
Check that there is no gap between actuator and adaption flange. It has to be
assured that there is proper contact in sealing area and around bolt areas.
3.
The rubber seat on the valve is soaped with water containing toilet soap.
4.
The hydraulic pressure is increased to the actuator test pressure, and the stop
screws/end stop is tightened.
5.
The disc is opened (speed is throttled).
6.
Nut/counter-nut is tightened.
7.
The disc is opened and closed at 2/3 of the hydraulic working pressure of the actuator.
8.
If the disc is askew, please contact Emerson.
9.
After adjustment, the valve shall be opened, so that the disc is clear of the rubber.
a = guiding dimension
ø = valve diameter
a = tan
α
x Ø
a
α
Ø
16
Section 5: Adjusting the Valve Disc
