ASAHI AV VALVES Installation,Operation and Maintenance Manual
Constant Flow Valves
6
(7)
Operating procedure
○
To operate the valve for opening / closing, turn the hand wheel slowly.
( To get the flow rate decreased, turn the hand wheel clockwise.)
To set new flow rate, turn the hand wheel counterclockwise to let the indicator of opening
degree reach beyond the required level and then the hand wheel clockwise to obtain proper
flow rate .
( This is the recommendable procedure to get exact flow rate.)
○
To shut the valve, turn the hand wheel clockwise, and adjust the indicator to the “ 0 ” position of the
flow rate scale.
Application of rubber material for shut – off seat gives the valve perfect closing with little tightening
torque.
Do not operate the valve out of scale, especially at lower level than the minimum indicated scale.
(The function of valve could be deteriorated.)
(8) Inspection items
○
Inspect the following items
(1)
Existence of scratches, cracks, deformation, and discoloring.
(2)
Existence of leakage from the valve to the outside.
(3)
Existence of leakage when the valve is opened fully at right or left.
(9) Troubleshooting
Problem Cause
Treatment
Insufficient Working differential
pressure.
Adjust Working differential pressure.
Foreign materials are caught.
Clean.
Appearance of algae or seaweed on
the surface of valve inside.
Clean.
The flow rate is
extraordinarily small
Sand is caught in the valve.
Clean.
The plug is damaged or worn.
For further detail and assistance, consult
your nearest AOC agents / branches.
The orifice is damaged or worn.
For further detail and assistance, consult
your nearest AOC agents / branches.
It has exceeded beyond the range of
Working differential pressure.
Adjust Working differential pressure.
Appearance of algae or seaweed on
the surface of valve inside.
Clean.
The flow rate is larger
than the range of
recommended flow rate.
Sand is caught in the valve.
Clean.
Appearance of algae or seaweed on
the surface of valve inside
Clean.
Fluid is not stopped in
the full shut position.
Sand is caught in the valve.
Clean.
Caution
Caution