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※There is a possibility that the handle is
stuck and cannot be removed. It is easier
to turn the handle to obtain high reduced
pressure if a screwdriver(axis diameterφ6)
is used as follows.(For the nominal sizes of
40A and 50A)
(1) Lift up the handle to unlock.。
(2) Insert a screwdriver in the handle through
notches, and turn it to the left or right.
8.
Maintenance Procedure
8.1 Troubleshooting
Problem
Pressure does not
rise to the desired
level.
Reduced pressure
exceeds prescribed
level.
Abnormal noise is
heard.
8.2 Precautions during maintenance and inspection
Warning
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)In order to maintain original performance and function, examine daily and personal inspection. And,
periodical inspection must be examined according to the regulations of every kind.
※ For general users, request to specialized in dealer or manufacture.
(2)Pressure reducing valve shall be disassembled and inspected by qualified person or manufacture.
※ Request the treatment to specialized dealer or manufacture in case of any problems.
(3)While disassembly, drain flow out from the valve, so catch it by container. And release steam completely
before disassembling.
※In case of no container for drain, it makes dirty surrounding the valve.
(4)Close the stop valves before and after the reducing valve, and remove all foreign matter and scales via
the by-pass line before operation.
※ Failure to do so may result in the valve from functioning incorrectly.
Cause
1.Incorrect pressure is being used.
2.Nominal size is too small for these
specifications.
3.Incorrect adjustment.
4.Screen is clogged.
5.Pressure gauge malfunction.
1.Foreign matter is embedded in the valve and/or
valve seat, or else scratches exist.
2.Reduced pressure sensing hole is clogged with
foreign matter.
3.By-pass valve is leaking.
1.Pressure reduction ratio is too large.
2.Drainage problem.
3.An abrupt open/close valve is located too close
to the pressure reducing valve.
1.Correct the pressure.
2.Replace with the correct nominal sized
item.
3.Re-adjust according to the adjustment
procedure.
4.Disassemble and clean.
5.Replace the pressure gauge.
1.Disassemble and clean. If scratches
exist, polish them away.
2.Disassemble and clean.
3.Repair or replace the valve.
1.Use a two-stage reduction.
2.Install a trap.
3.Move distance as much as possible
between the valves.
6
Solution
■PDT－136a■
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