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7.2 Precaution for maintenance and inspection
1. Completely discharge the pressure inside of the product, piping and equipment prior to disassembly
and inspection. When fluid is hot, cool down the product to the condition that it can be touched with
bare hands. Avoid touching the product with bare hands till it is cooled down enough.
* Failure to follow this notice may result in scalds, injury or contamination on the surroundings due
to the residual pressure.
1. Disassembly and maintenance must be conducted by professional.
* In the event of product failure, ask a professional to take measures.
2. When disassembling, put a container under the product to collect condensate flowing out from it.
Disassemble the product after condensate is completely discharged from the product.
* Failure to follow this notice may result in making the surroundings dirty.
3. Before applying steam to the product, close the stop valves at the inlet and outlet sides of the product
and remove foreign substances and scale from the piping completely.
* Failure to follow this notice may prevent the product from functioning properly due to the ingress of
foreign substances and scale into the product.
4. Before stopping operation of the product for an extended period, completely discharge the fluid from
the product and close the stop valves at the inlet and outlet sides of the product.
* Failure to follow this notice may cause malfunction due to rusting inside of the product and the
pipes.
5. After stopping operation of the product for an extended period, conduct operational check of the
product.
* In the event of product failure, ask a professional to take measures.
7.3 Disassembly
Before disassembly, be sure that the stop valves at the inlet and outlet sides of pressure reducing
valve are closed. Be careful that all internal pressure and condensate are discharged.
(1) Disassembly of the main valve
1. Remove the bolt [15] from the cover [4] to dismount the cover from the body [1]. At the same time,
remove the main valve spring [12] and main valve [5].
(2) Disassembly of the main diaphragm
1. Remove the bolt [20] from the bottom diaphragm case [3]. Dismount the bottom diaphragm case,
at the same time, remove the main diaphragm [11] and retainer [10].
7.4 Precautions for reassembly
1. Check that there are no scratches on the main valve and main valve seat.
* Any scratches at sealing surface lead to increase in secondary pressure. When any scratches are
identified on the main valve or main valve seat, make lapping of them. Please contact us if scratches
still exist after lapping.
2. Confirm that the sliding parts (the spindle) moves smoothly.
* If the sliding parts do not move smoothly, it may cause failure problems.
3. Replace gaskets with new ones when reassembling.
* If the old gasket is used again, it may cause steam leakage problem.
4. Assemble the parts in reverse order from disassembly. Tighten the bolts uniformly.
* Wrong order keeps the product from being assembled correctly. If the hexagon bolts are not tightened
uniformly, it may cause steam leakage problem.
Warning
Caution
Caution
15
EPDT-021a
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