-8-
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EPDT-209
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8.1 Warning and precaution on maintenance and inspection
Warning
The pressure reducing valve shall be disassembled and inspected by qualified persons.
( 1 ) Completely discharge internal pressure from the valves, lines, and equipment, and cool
the valve down to a level where you can touch it with bare hands before disassembly and
inspection.
*Failure to do so may result in injury or burns due to residual pressure or spillage
around the valve.
Caution
( 1 ) To maintain the functions and performance of pressure reducing valve, perform
periodical inspection.
*User should request to specialized dealer or manufacturer for such tasks.
( 2 ) Pressure reducing valve should be disassembled and inspected by qualified person or
manufacturer.
*Request the treatment to specialized dealer or manufacturer in case of any problems.
( 3 ) During disassembling, internal fluid flows out. Discharge it into a suitable container.
Disassembling pressure reducing valve after all fluids have been discharged.
*Fluid spills will contaminate surroundings.
( 4 ) Close the stop valves before and after pressure reducing valve, and remove all foreign
matter and scales via the by-pass line before operation.
*Failure to do so may cause the malfunction of pressure reducing valve.
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Consumable parts and replacement period
Service life of consumable parts is dependent on the frequency and condition of usage. Rough
indication of service life is given below.
(Refer to the parts number in “3.2 Construction”)
Name of parts
No.
Replacement period
Diaphragm (9) 3
years
Disc (6)
3
years
O-ring (18)
3
years
8.2 Troubleshooting
(Refer to the parts number in “3.2 Construction”)
Problem Cause Countermeasure
Reduced pressure
exceeds prescribed
level.
1. Diaphragm(9) is damaged.
2. Foreign matter is embedded in
the valve(6) and/or valve seat(5),
or else scratches exist.
1. Replace the diaphragm(9).
2. Disassemble and remove the
foreign mater.
If scratches exist, replace it.
Pressure does not
rise to the desired
level.
1. Strainer is clogged.
2. Pressure gauge malfunction.
1. Disassemble and clean.
2. Replace the pressure gauge.
Leakage
1. Loosen Bolt(19).
2. Loosen Cap(3).
3. Broken O-ring(18) for cap.
1. Tighten Bolt(19).
2. Tighten Cap(3).
3. Replace O-ring(18) for cap
new one.
Abnormal noise is
heard.
1. The suspension metal(7) is in
incorrect position.
1. Correct the position of the
suspension
metal(7).
