Maintenance And Inspection; Troubleshooting - Yoshitake CT-1 Product Manual

10．Maintenance and inspection
10.1 Troubleshooting (Please see the structure described 4)
Problem
Not working
Working is
unstable
Leakage from
valve⑤
Leakage from
grand packing⑥
or gasket part⑧
Cause
1．Operating pneumatic
pressure or external signal
are not supplied.
2．Air piping is clogged or
leaked.
3．Diaphragm bolt is loosen.
4．Leakage is happened
between bottom diaphragm
case and diaphragm rod.
5．Failure is occurred on
accessories of positioner or
regulator.
6．Failure is occurred on body
part or actuator
7．Sensitivity of the positioner is
inadequate.
1．Abnormal signal from the
controller
2．Operating pneumatic
pressure is not constant.
1．The valve does not move to
the full closed position ( Not
moving downward )
2．There are any scratches on
the valve seat③1 or valve⑤
1．The nut on grand part⑳ or
body part⑪ is loosen.
2．The harden pf the grand
packing⑥ or gasket⑧
-17-
Solution
1．Please confirm the presence or
absence of the operating air
(more than 0.35MPa) by the
pressure gauge, etc. And
confirm the external signal
tester by using tester.
2．In case of clogged, please clean
it. When leaking, please replace
the piping.
3．Retighten it.
4．Replace the product.
5．Inspect or replace the positioner
or regulator.
6．Inspect or replace the product.
7．Replace the positioner.
1．Adjust controller again and
confirm the signal system.
2．Check the air piping and
exchange it to the bigger piping
diameter.
1．Adjust the zero point again by
using the controller.
2．Replace the product.
1．Retighten the nut. After
retightening, there is still leak,
exchange the packing.
2．Replace them.
■ EPDT-318a ■