5-4
5-3. Cleaning the flapper
If contamination from the instrumentation air has accumulated on the flapper, clean the
flapper as described below.
CAUTION
If air pressure is supplied to the SVP, the nozzle back pressure may change causing the valve
position may change suddenly when the flapper is cleaned. Only clean the flapper in a state
where no one will be injured and plant operation will not be adversely influenced even if the
valve moves suddenly.
Procedure
Step No. Procedure
1 Remove the cover.
2 Remove four screws from the cover plate.
3 Remove the plate by sliding it to the left.
4
Provide pieces of paper with a thickness of 0.2 mm. Standard business cards will
do.
5
Use the scraps of paper to clean the contamination from the gap between the
EPM nozzle and the flapper.
6 After cleaning the gap, reassemble the plate and cover.
Cover plate
EPM adjustment screw
Business card
Approx.
0.2 mm
Fig. 5-5. EPM balance adjustment