Yoshitake GP-1200 User manual

■EPDT-101■
Model GP-1200&GP-1210
PRESSURE REDUCING VALVE
Installation & Operation Manual
Please read this bulletin thoroughly before using the pressure reducing valve, so that you may
do so correctly and safely. Please carefully store this bulletin in a handy place.
―――――――――The following safety symbols are used in this manual. ――――――――


Warning


Caution
Contents
1. Features･････････････････････････････････････････････････････ 1
2. Specifications････････････････････････････････････････････････ 1
3. Dimensions and Weights･････････････････････････････････････ 2
4. Operation････････････････････････････････････････････････････ 3
5. Nominal Size Selection Method
5.1 Standard loading pressure -setting pressure
chartline･････････････････････････････ 3
5.2 Specifications selection chart ･････････････････････････････ 4
5.3 Safety valve setting pressure chart ･･･････････････････････ 4
5.4 Characteristics chart･･････････････････････････････････････ 4
5.5 Nominal size selection chart ･･････････････････････････････ 5
5.6 Nominal size selection calculation formula ････････････････ 6
6. Installation
6.1 Example of piping ････････････････････････････････････････ 6
6.2 Precautions during installation ････････････････････････････ 7
7. Operating Procedure
7.1 Precautions during operation ･････････････････････････････ 8
7.2 Adjustment procedures･･･････････････････････････････････ 8
8. Maintenance Procedure
8.1 Troubleshooting ･･････････････････････････････････････････ 9
8.2 Precautions during maintenance and inspection ･････････ 10
8.3 Disassembly･････････････････････････････････････････････ 10
8.4 Precautions during reassembly ･･････････････････････････ 11
8.5 Exploded drawing ･･･････････････････････････････････････ 12
After Sale Service
This symbol indicates a potentially hazardous situation that, if not
avoided, could result in death or serious injury.
This symbol indicates a hazardous situation that, if not avoided, may
result in minor or moderate injury. (“Caution” may also be used to
indicate other unsafe practices or risks of property damage.)

■EPDT-101■
‑1‑
1. Features
GP-1000 Series pressure reducing valves for steam are pilot-operated valves which can be used with
confidence for small to large flow rate, in a host of applications ranging from building utilities systems,
air-conditioning systems, and factory systems, etc.GP-1200 and 1210 models can be used as pneumatic,
remote type valves, making them well suited for systems where the pressure setting is frequently
changed, or for centralized control system.
2. Specifications
Model GP-1200 GP-1210
Connection Flanged (JIS 10K FF) JIS Rc Screw
Nominal size 15～100A 15～50A
Application Steam
Inlet pressure 0.1～1.0 MPa
0.05～0.9 MPa
Reduced pressure 90% or less of inlet pressure (gauge pressure)
Loading air pressure See the “Standard loading pressure-setting pressure chart line”. (P.3)
Min. differential pressure 0.05 MPa
Max. pressure reducing ratio 20：1
Max. temperature 220℃
Valve seat leakage 0.01% or less of rated flow
Body Ductile cast iron
Valve Stainless steel
Valve seat Stainless steel
Piston/Cylinder Brass or Bronze
Material
Gasket Non asbestos
Body hydraulic test 2.0 MPa
lStainless steel main components (piston & cylinder) are also available. (GP-1200S,1210S)
lStainless steel type is also available for GP-1200 [15-50A]. (GP-1200SS: Wetted parts stainless steel)
Caution
(1) Please collate with attached nameplate and specification of ordered model.
※Please consult factory in case they do not match each other.

■EPDT-101■
‑2‑
Rc1/4 Air loading
pressure port
Rc1/4 Air loading
pressure port
3. Dimensions and Weights
•ＧＰ－1200
(㎜)
Size ＬＨＨ
１Weight（kg）
15A 150 220 64 8.0
20A 155 220 64 8.5
25A 160 235 67 10.0
32A 190 258 82 14.0
40A 190 258 82 14.5
50A 220 282 93 20.0
65A 245 292 100 30.0
80A 290 339 122 35.0
100A 330 385 144 52.5
•ＧＰ－1210
(㎜)
Size d ＬＨＨ
１Weight（kg）
15A Rc 1/2 150 220 64 7.0
20A Rc 3/4 155 220 64 7.0
25A Rc 1 160 235 67 8.5
32A Rc 1-1/4 190 258 82 12.0
40A Rc 1-1/2 190 258 82 12.5
50A Rc 2 220 282 93 18.0

■EPDT-101■
‑3‑
Rc1/4 Air loading
pressure port
4. Operation
No. Parts name
1 Body
8 Pilot diaphragm
9 Main valve
11 Main valve seat
12 Piston
13 Cylinder
17 Pilot valve
18 Pilot valve seat
26 Strainer
41 Inlet press. passage
42 Reduced press. Sensing port
43 Diaphragm chamber
44 Air chamber
The pressure reducing valve reduces pressure by the throttling the valve. The valve is composed of the
main valve and main valve seat for throttling, and air pressure control space, diaphragm, pilot valve, and
piston for pressure sensing and activation.
(1) When the pressure reducing valve is mounted correctly, main valve [9] and pilot valve [17] should
be closed when air pressure is no-pressure because of spring force. Slowly open the gate valve and
allow the high pressure fluid to flow in. Inlet pressure is applied to the downside of the main valve.
High pressure fluid passes through strainer [26] via inlet pressure passage [41] to also apply inlet
pressure to the downside of the pilot valve.
(2) Introducing air pressure into air chamber [44] flexes pilot diaphragm [8] to open the pilot valve.
(3) Inlet pressure via inlet pressure passage and pilot valve enters the upside of the piston. The pressure
overrides the pressure on the downside of the main valve and the load of main valve spring, to open
the main valve. The fluid then begins to flow from the inlet side.
(4) Reduced pressure is led to diaphragm chamber [43] via reduced pressure sensing port [42]. The
diaphragm receives the reduced pressure to be balanced with the air loading pressure, and control
the pilot valve travel.
(5) The change of pilot valve travel changes the flow rate of fluid to the upside of the piston, and
controls the main valve travel to obtain appropriate reduced pressure.
5. Nominal Size Selection Method
5.1 Standard loading pressure-setting pressure chart line
The setting pressures corresponding
to the loading pressure are shown left.
(P1: 1.0 MPa) As slight deviations
from the loading pressure-setting
pressure chart line shown left may
occur depending on conditions, such
as the length of the air line, etc., a
setting pressure which is high enough
to cover such deviations should be
selected.
SettingpressureMPa
LoadingpressureMPa
0.8
0.6
0.4
0.2
01.00.80.60.40.2

■EPDT-101■
‑4‑
5.2 Pressure reducing valve specification selection chart
Find the intersection point of the
inlet and reduced pressures. The
GP-1200 (1210) valves are suitable
within range (A). When within
range (B), maximum performance
cannot be obtained.
5.2 Safety valve setting pressure chart
Determine the reduced pressure of
pressure reducing valve. Find the
intersection point (A) with the chart
curve. Next, find point (B) by
proceeds horizontally from point (A)
to the left until the ‘Setting pressure
of safety valve’ axis. The setting
pressure of the safety valve should
be higher than the pressure of the
point (B).
5.3 Characteristics chart
(1) Flow rate characteristics chart
•Shut-off pressure raise : 0.02 MPa or less
•Offset : 0.03 MPa or less
(Setting pressure: 0.05~0.1 MPa)
: 0.05 MPa or less
(Setting pressure: 0.1~0.9 MPa)
(2) Pressure characteristics chart
Reduced pressure is set to 0.1 MPa
when inlet pressure is 1.0 MPa. The
chart indicates a variation in reduced
pressure when the inlet pressure is
changed from 1.0 to 0.3 MPa.
ReducedpressureMPa
0.80.60.40.2
1.6
1.2
0.8
0.4 BA
Settingpressureof safetyvalve MPa
0
10050
Offset
Shut‑offpressureraise
5Flowrate
Setting
pressure
(%)0
Reduced pressure
Min.adjustableflowrate Ratedflow
0.8
0.08
InletpressureMPa
1.0
0.60.40.2
0.16
0.14
0.12
0.10
ReducedpressureMPa
0
0.1 0.8 0.9 0.70.60.50.40.30.2
0.6
1.0
0.8
0.4
0.2
InletpressureMPa
ReducedpressureMPa
Controllablerange(A)
Maximumperformance
isimpossiblewithin
thisrange(B)

■EPDT-101■
‑5‑
5.4 Nominal size selection chart
[Ex.1]
For example, take a pressure reducing valve whose inlet pressure (P1) is 0.6 MPa, reduced pressure (P2)
is 0.4 MPa, flow rate 800 kg/h. First, find the point of intersection (A) of inlet pressure 0.6 MPa and
reduced pressure 0.4 MPa. Vertically proceed from point (A) to come across the flow rate 800 kg/h,
and regard this point as (B). Point (B) is between nominal sizes 40A and 50A. Select the larger
nominal size 50A.
[Ex.2]
For example, take a pressure reducing valve whose inlet pressure (P1) is 0.8 MPa, reduced pressure (P2)
is 0.05 MPa, flow rate 600 kg/h. First, find the point of intersection (C) of inlet pressure 0.8 MPa and
the diagonal line. Move leftward down the diagonal line to intersection point (D) where the diagonals
line intersect with the reduced pressure 0.05 MPa. Vertically proceed from point (D) to come across
the flow rate 600 kg/h, and regard this point as (E). Point (E) is between nominal sizes 32A and 40A.
Select the larger nominal size 40A.
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
(E)
(D)
(B)
(A)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
200
10000
8000
10000 8000
10
100A
80A
65A
W:Flowratekg/h
1
:InletpressureMPa
P
2
：ReducedpressureMPa
300
20
800
600
400
Nominal
size
50A
40A
32A
25A
20A
15A
(C)
600
800
1000
2000
3000
4000
6000
6000 4000 3000 2000 1000
400
300
200
100
80
60
40
30
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
P
P
2
：ReducedpressureMPa
W:Flowratekg/h

■EPDT-101■
‑6‑
5.5 Nominal size selection calculation formula
The appropriate nominal size can be calculated by obtaining the Cv value for the operating conditions
in question, as shown below.
•Cv value calculation formula
•Rated Cv value table (When Cv correction coefficient is C=1)
Nominal size 15A 20A 25A 32A 40A 50A 65A 80A 100A
Rated Cv value 1 2.3 4 6.5 9 16 25 36 64
※Correction of rated Cv value
If the inlet pressure exceeds 0.7 MPa, and the pressure reducing ratio exceeds 10:1,
find the appropriate correction coefficient C using chart below, and multiply the rated
Cv value, and obtain the corrected Cv value.
[Ex.]
Take a pressure reducing valve whose inlet
pressure is 0.8 MPa, reduced pressure is 0.05
MPa. Find the inlet and reduced pressure
intersection point (A) at the left chart, then
draw a horizontal line in the leftward
direction to point (B) which indicates a
correction coefficient of 0.85. For a nominal
size of 25A, the corrected Cv value would be
calculated as follows:
4(rated Cv value) ×0.85(correction
coefficient) = 3.4
6. Installation
6.1 Example of piping
W: Max. steam flow rate [kg/h]
P1: Inlet pressure [MPa･A]
P2: Reduced pressure [MPa･A]
ΔP: P1−P2 [MPa]
k: 1+0.0013 ×{super-heated steam
temp.[℃]−saturated steam
temp.[℃]}
2
P
P1
2>
)PP(P138
Wk
Cv 21 +∆ =
2
P
P1
2<
1120P
Wk
Cv =
Air pressure
Non-return
valve
Standard unit
3 port
solenoid valve
Stop
valve GP-1200
Pressure reducing valve
Safety
valve
Reducer
Blow
1810
Trap
Sight glass
By-pass
stop valve
Strainer
Drain separator
DS-1
Pressure
gauge Pressure
gauge
Stop
valve
Stop
valve
Stop
valve
Relief
pipe
P:ReducedpressureMPa
0.100.080.060.040.02
(B) (A)
1.0
0.9
0.8
0.7
0.9
0.8
C:Correction coefficient
P
1
:InletpressureMPa
0
0.7
1.0
2

■EPDT-101■
‑7‑
6.2 Precautions during installation
Warning
(1) Because of heavy weight, hold the valve with lifting equipment while piping. Refer to
“3. Dimensions and Weights” table for the valve weight.
※Failure to do so may result in injury due to dropping the valve.
(2) In case installing safety valve as safety device at outlet side, joint relief pipe at outlet
of safety valve and guide it to safety place where steam can relief out.
※Failure to do so may result in burns.
Caution
(1) Do not disassemble the valve unreasonably.
※Disassembling the valve at your discretion may affect the original performance.
(2) Remove foreign matter and scales from the lines before connecting the valve.
※Failure to do so may prevent the valve from functioning correctly.
(3) Install a strainer (Recommendation: 100-mesh or equivalent) at the valve inlet side.
※Failure to do so may hamper correct pressure control, which affects the original
performance.
(4) Install a safety valve at the valve outlet sides as safety device for equipment.
※Failure to do so prevents problem identification, resulting in equipment damage.
(5) Install a pressure gauge at both the inlet and outlet sides of the valve.
※Failure to do so may hamper correct pressure adjustment.
(6) Install 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.
(7) When installing quick open and close valves, such as a solenoid valve, install it at
inlet side as much as possible, and secure at least 3 m from the valve.
※Failure to do so may result in malfunction or drastically shortened service life.
(8) When pressure reducing in two stages, secure at least 3 m between the valves.
※Failure to do so may result in malfunction, affecting the original performance.
(9) Install the valve in proper direction of the fluid flow.
※Failure to do so may affect the original performance.
(10) Do not apply excessive load, torque or vibration to the valve.
※Doing so may result in malfunction or drastically shortened service life.
(1) Install the valve perpendicularly to horizontal lines.
(2) Provide the by-pass line. (See 6.1 Example of piping)
(3) When the pressure reducing ratio is large, install a reducer to keep the flow velocity in the pipe
below 30 m/s or less.
(4) Provide space on the top and bottom of the valve so that the valve can be easily disassembled
and inspected. (See Fig.1)
(mm)
Fig.1
Nominal
size AB
15A
20A 125
25A 240 135
32A
40A 260 155
50A 270 175
65A 280 190
80A 300 225
100A 320 265
A
B

■EPDT-101■
‑8‑
7. Operating Procedure
7.1 Precautions during operation
Warning
(1) Do not touch the valve directly with bare hands.
※Doing so may result in burns.
(2) Before flow the steam in pipe line, make sure steam can flow without any dangerous at
the end of pipe line and pipe line is connected tightly.
※In case steam blow off, it may result in burns.
Caution
(1)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. And, open each stop
valve slowly.
※Failure to do so may prevent the valve from functioning correctly. And, It may cause
hunting, water hammer, etc., resulting in damage to the valve and other equipment
when the stop valve is opened quickly.
(2)Secondary pressure at by-pass line must be lower than set pressure.
※Safety valve blows in case secondary pressure at by-pass line becomes higher than
set pressure.
(3)When adjusting pressure, slowly increase loading air pressure.
※Incorrect adjustment may cause hunting, water hammer, etc., resulting in damage to
the valve and other equipment.
(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.
7.2 Adjustment procedures
Follow the steps below, and slowly turn the adjusting screw to set pressure. Incorrect adjustment may
cause hunting, water hammer, etc., resulting in damage to the valve and other equipment.
（1）Close the stop valve at inlet and outlet side of the pressure reducing valve, and taking sufficient
time not to blow the safety valve, blow off the fluid to remove foreign matter via the by-pass
line. After blowing, close the by-pass line stop valve.
（2）Slowly open the stop valve at the inlet side of the pressure reducing valve, and adjust the travel of
the stop valve at the outlet side of the pressure reducing valve so that a little fluid flows.
（3）Set operating air pressure to no-pressure. And slowly increase the operating pressure until the
desired pressure is reached while observing the pressure gauge on the outlet side.
（4）Slowly open the stop valve at the outlet of the pressure reducing valve, and readjust the desired
pressure.
（5）After adjustment, secure the handle of the standard unit’s pressure reducing valve.

■EPDT-101■
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8. Maintenance Procedure
8.1 Troubleshooting
Problem Cause Solution
Pressure does not
reach the desired
value.
1．Incorrect pressure is being used.
2．Strainer [26] is clogged.
3．Foreign matter exists between
piston [12] and cylinder [13].
4．Piston ring [14] is damaged.
5．Nominal size is too small for the
specifications.
6．Pressure is not adjusted correctly.
7．Strainer installed before pressure
reducing valve is clogged.
8．Pressure gauge is faulty.
9．Operating air pressure is being in-
sufficient.
1．Correct the pressure.
2．Disassemble and clean the strainer.
3．Disassemble and remove the foreign
matter. When any scratches are
identified, polish them away using a
paper. Change the parts if scratches
still exist after polishing.
4．Replace the piston ring.
5．Change the nominal size appro-
priately.
6．Observe the adjustment procedures
and readjust pressure.
7．Disassemble and clean it.
8．Replace it.
9．Raise the operating air pressure to
necessary set pressure.
Reduced pressure
raises above than
the specified value.
1．Foreign matter exists between
main valve [9] and main valve seat
[11], or scratches exist.
2．Foreign matter exists between
pilot valve [17] and pilot valve seat
[18], or scratches exist.
3．Foreign matter exists between
piston [12] and cylinder [13].
4．Trap is not provided for dead-end
line.
5．By-pass valve is leaking.
6．Diaphragm [5] is damaged.
1．Disassemble and remove the foreign
matter. When any scratches are
identified, lap the main valve and
main valve seat. Change the parts if
scratches still exist after lapping.
2．Disassemble the pilot valve as-
sembly, and clean or replace it.
3．Disassemble and remove the foreign
matter. When any scratches are
identified, polish them away using a
paper. Change the parts if scratches
still exist after polishing.
4．Install a trap.
5．Repair or replace it.
6．Replace the diaphragm.
Abnormal noise is
heard.
1．Nominal size is too large for the
specifications.
2．Pressure reducing ratio is too large.
3．Drainage problem is caused.
4．An abrupt OPEN/CLOSE valve is
located too close to the pressure
reducing valve.
5．Outlet pipe is too small.
1．Change the nominal size appro-
priately.
2．Reduce pressure in two stages.
3．Install a trap.
4．Allow as much as possible between
the valves.
5．Select a pipe size that will produce a
flow velocity of 30m/s or less.
Other 1．Springs and diaphragm are worn. 1．Replace the springs and diaphragm.
lForeign matter and scales in a pipe may cause most of problems of pressure reducing valve. Be
careful sufficiently to foreign matter in a pipe.
lPhenomenon 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
particulars before above troubleshooting.
lConsult factory when cannot make a judgement whether parts need replacement or not.

■EPDT-101■
‑10‑
8.2 Precautions during 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. And set operating air pressure to no-pressure.
※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 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 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.
(5)When adjusting pressure, slowly increase loading air pressure.
※Incorrect adjustment may cause hunting, water hammer, etc., resulting in damage to
the valve and other equipment.
(6)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.
(7)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.
8.3 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 operating air pressure to no-pressure.
2．Remove bolt [31] of cover [4]. Remove the cover, pilot diaphragm [8], diaphragm plate [6],
diaphragm case [7], and diaphragm [5].
3．Remove the pilot valve assembly [17], [18] using a ring spanner or socket wrench (nominal size
22)
(2) Piston
1．Remove bolt [32] of top cover [2] and the top cover. Pick up spindle [16], and remove piston
ring [14] and inner ring [15].
(3) Main valve
1．Remove bolt [33] of bottom cover [3]. Remove the bottom cover, main valve spring [10], and
main valve [11].

■EPDT-101■
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8.4 Precautions during disassembly
Caution
(1) Check that there is no damage and scratches on the main valve, main valve seat, pilot
valve, and pilot valve seat.
※Any scratches at sealing surface lead to increase in secondary pressure. When any
scratches are identified at main valve and seat, polish them away. And, change 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 valve, piston, etc.) two to three times and confirm they
move smoothly.
※If the sliding parts do not move correctly, it may cause failure problems. (Working not
correctly).
(3) Replace gaskets with new ones when reassembling.
※If the gasket is used for a long time, it may cause steam leakage problem.
(4) Assemble in the reverse order of Disassembly. And tighten the bolts evenly.
※Assemble the valve due to the order. Failure to do so may lead to not assemble
correctly. And if the hexagon bolts are not screwed correctly, it may cause steam
leakage problem.

■EPDT-101■
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8.5 Exploded drawing
Parts with in the flame are consumable. Please contact us for purchase of these consumable parts.
№Name of parts Replace period
5 Diaphragm 2 years
14 Piston ring 3 years
15 Inner ring 3 years
17･18 Pilot valve assembly 5 years
22 Gasket 5 years
24･25 Gasket 2 years
26 Strainer 5 years
28 Gasket 2 years
8 Pilot diaphragm 2 years
Note (*): Apply a liquid sealant for heat and steam resistant (Recommendation: NEVER
SEEZ Standard grade) to the sealing surface of the diaphragm bottom and the top
cover, and pilot diaphragm top and the cover.