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EPDT-098a

 

  -16- 

 

● Foreign matter and scales in a pipe may cause most of problems of pressure reducing 

valve. Be careful sufficiently to foreign matter in a pipe. 

● Phenomenon alike valve trouble may happen by fault of pressure gauge, fluid leakage 

from by-pass valve, forgetting to close the by-pass valve, clogging strainer, and etc. 
First, check the said before above troubleshooting. 

● Consult factory when cannot make a judgement whether parts need replacement or not. 

 

7.2 Precautions for maintenance and inspection 

Warning

 

(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)  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. 

(2) 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. 

(3) Close the stop valves before and after the pressure reducing valve, and remove all foreign 

matter and scales via the by-pass line before operation. 
* Failure to do so may prevent the valve from functioning correctly. 

(4) Remove condensate completely from the line, and close the stop valves before and after the 

valve when not using it for long periods of times. 
* Rust generated in the valves and lines may cause malfunction. 

(5) In case of no operation for a long period of time, perform operating exam before start operation 

again. 
* Request the treatment to specialized dealer or manufacture in case of any problems. 

 

7.3 Disassembly 

Be sure that the stop valves at inlet and outlet side of pressure reducing valve is closed and 
all internal pressure and condensate have discharged before disassembling the valve. 

 

(1) Pilot valve 

1. Set the operating air pressure to no pressure. 
2. Remove bolt [60] of cover [57]. 
3.  For  GPK-2001,  remove  the  pilot  diaphragm  [23],  the  diaphragm  case  [58],  and  pilot 

diaphragm plate [59]. 

3. Remove pilot valve assembly using a ring spanner or socket wrench (nominal size 22). 

 

(2) Main valve 

1. Remove pipe A [34] at joint A [30] or tee [33]. 
2. For nominal sizes 15A to 40A, remove bolt [38] of pilot body [2]. Dismount the pilot body 

from the body [1]. And remove spring plate [14], screen [15], main valve spring [13], and 
main  valve  [6].    For  nominal  sizes  50A  to  100A,  remove  bolt  [44]  of  spacer  [54]  and 
remove the spacer from the main body [1], main valve spring [13], and entire main valve 
([6], [9], [50], and [51]) (for nominal size 50A, main valve spring, and main valve [6]) 

 
 
 

Содержание GPK-2001

Страница 1: ...Nominal size selection calculation formula 10 5 Installation 5 1 Precautions for installation 11 5 2 Installing accessories 11 5 3 Piping before and after the pressure reducing valve 12 5 4 Example o...

Страница 2: ...sure 0 05 0 9 MPa JIS Rc JIS 20K 0 05 0 85 MPa JIS 10K 0 2 1 4 MPa JIS Rc JIS 20K 0 2 0 85 MPa JIS 10K 85 or less of inlet pressure gauge pressure System air pressure Refer to Standard Loading pressur...

Страница 3: ...nal Size Screw JIS Rc Flanged JIS 20K RF d L H H1 A Weight kg L H H1 A Weight kg 15A Rc 1 2 150 335 170 200 14 0 146 335 170 200 15 5 20A Rc 3 4 150 335 170 200 14 0 146 335 170 200 16 0 25A Rc 1 160...

Страница 4: ...17 5 146 353 170 200 19 5 25A Rc 1 160 359 175 226 22 0 156 359 175 226 24 5 32A Rc 1 1 4 180 389 192 226 25 0 176 389 192 226 27 5 40A Rc 1 1 2 180 389 192 226 25 0 196 389 192 226 28 0 50A Rc 2 230...

Страница 5: ...e Seat 23 Pilot Diaphragm 23 2 Air pressure sensing port 33 Tee 34 35 36 Pipe A B C 12 1 Main diaphragm chamber 23 1 Pilot diaphragm chamber 56 1 Reduced pressure sensing port 1 When the pressure redu...

Страница 6: ...36 This fluid also flows to the reduced side of the body 1 through the orifice of tee 33 and pipe 35 that connects to the body Fig 2 3 When the flow rate at the pilot valve exceeds the flow rate at th...

Страница 7: ...agm receives the reduced pressure to be balanced with the air pressure The pilot valve travel is controlled by the air pressure and pressure applied to the pilot diaphragm due to variations in reduced...

Страница 8: ...m performance cannot be obtained When reducing pressure in two stages maximize the distance between the valves at least 3 m 4 2 Safety valve setting pressure chart This chart is for setting the safety...

Страница 9: ...sidering pressure loss and heat loss of the gate valve and the strainer before and after the pressure reducing valve To fully utilize the flow characteristics of the valve do not select a small pipe s...

Страница 10: ...6 MPa reduced pressure P2 0 4 MPa flow rate 600 kg h When determining the nominal size find the point of intersection A of inlet pressure 0 6 MPa and reduced pressure 0 4 MPa Vertically proceed from p...

Страница 11: ...pressure reducing valve is calculated under the following conditions Nominal size 15A saturated steam Inlet pressure of 0 6 MPa 0 7 MPa A Reduced pressure of 0 4 MPa 0 5 MPa A you can find that Cv va...

Страница 12: ...alve from functioning 5 Do not connect the sensing pipe close to valves and elbows Choose the position with the least vibration Recommended straight length 10 times the line pipe diameter Failure to d...

Страница 13: ...stall a steam trap to the inlet sides of the valve to prevent drainage problems Failure to do so may result in drainage problem affecting the original performance 5 When installing quick open and clos...

Страница 14: ...is long the operating pressure set pressure basic diagram will deviate slightly In such cases change the operating pressure to achieve the required set pressure Standard operating circuit The standar...

Страница 15: ...ng screw to set pressure Incorrect adjustment may cause hunting water hammer etc resulting in damage to the valve and other equipment See 5 4 Example of piping 1 Check that all stop valves V1 to V7 ar...

Страница 16: ...in valve seat 12 or scratches exist 4 Foreign matter exists between pilot valve and pilot valve seat or scratches exist 5 Orifice of tee 33 is clogged 6 Reduced pressure is not adjusted correctly 7 Fo...

Страница 17: ...and remove all foreign matter and scales via the by pass line before operation Failure to do so may prevent the valve from functioning correctly 4 Remove condensate completely from the line and close...

Страница 18: ...ange the parts if scratches still exist after polishing Also in case any scratches are identified at pilot valve and pilot valve seat change into pilot valve assembly 2 Move the sliding section pilot...

Страница 19: ...n in the rectangle boxes are available as consumable supply Apply lubricant agent for heat steam resistance recommendation SOLVEST No 110 paste STT Inc to the bottom seal area of the pilot diaphragm a...

Страница 20: ...EPDT 098a 19...

Страница 21: ...improvement without any prior notice After the discontinuation of the product Yoshitake supplies the repair parts for 5 years otherwise individually agreed 3 This warranty does not cover the damage d...

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