Installation, Operation and Maintenance Manual
H-A058-E-12 Diaphragm Valve, True Union Diaphragm Valve (15-50mm, 1/2”-2”) Pneumatic Actuated Type AI
(17) Inspection items
- Perform periodic maintenance. (Leakage may develop due to temperature changes or over periods of
prolonged storage, rest or operation.)
○ Periodically inspect and maintain the AV valve in accordance with the plant schedule.
Portion to be inspected
- Existence of rust, peeling of paint, and dirt of inspection hole of valve travel indicator.
- Tightening condition of respective threaded portions. (Loose or not)
- Existence of rust and corrosion around the limit switch, and existence of internal
- Existence of abnormality in opening and closing operating sounds.
- Smooth operation of the valve. (more than once the 30 days)
* It is unnecessary to supply oil to this actuator.
- Existence of scratches, cracks, deformation, and discoloring.
- Existence of leakage from the valve to the outside.
- Existence of leakage when the valve is opened fully at right or left.
- Tightening condition of bolt (B). (loose or not)
(18) Disassembling method for replacing parts
The valve does not operate by
The power source of the control panel is
Turn on the power source.
The solenoid valve is disconnected.
Check the connection again.
(Refer to page 6, 17)
Air is not supplied to the solenoid valve.
Supply air to solenoid valve.
The supply voltage to the solenoid valve is
Check voltage with a tester and set
The voltage to the solenoid valve is low.
The bypass valve opens.
Close bypass valve by turning the
bypass valve knob in a clockwise
The speed controller’s knob is fully turned in a
Turn speed controller’s knob in a
counterclockwise direction.(Refer to
pages 19 and 20.)
The operation pressure is low.
Check the operating pressure.