Yoshitake GD-200 Series User manual

■EPDT-09b■

GD-200Series
Model GD-200、200C、200H

PressureReducingValve
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＆Performance
２．１Specifications·········································· 1〜2
２．２FlowRateCharacteristicsChart ························· 2
２．３PressureCharacteristicsChart ························· 2
３．Dimensions＆Weight ········································ 3
４．Operation···················································· 4
５．NominalSizeSelectionMethod
５．１NominalSizeSelectionChart ···························· 5〜6
５．２SelectionFormulaforNominalSize ······················ 7
６．Installation
６．１Precautionsbeforeoperation ··························· 8〜9
６．２ExampleofPiping······································· 9
７．OperatingProcedure
７．１Precautionsforpressurereducingvalveoperation ····· 10
７．２AdjustmentProcedure···································· 11
８．MaintenanceProcedure
８．１Troubleshooting········································· 12
８．２Precautionsduringdisassemblyandinspection ········· 13
８．３disassembly ············································· 13〜14
８．４Precautionsduringdisassembly ························· 14
８．５Explodeddrawing········································ 15
AfterSales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.

-1-■EPDT-096b■
GD-200Seriespressurereducingvalvesarewidelyusedforconstruction
equipment,airconditioning,plantequipment,industrialplantfacilitiesand
otherapplication.
Thisproductcanprovidestableoutletpressureandbigcapacity.
１．Features
  １)Aspressurebalancedstructureisintroduced,outletpressurecanbekept
ataconstantlevelwithoutinfluenceofinletpressure.
  ２)Valveseatismadeofstainlesssteeltoensuresuperiorpreventingabrasion
anddurability.
  ３)Rubberdiscisusedatthevalvebodytoeffectivelyeliminateleaks.
  ４)Maintenanceiseasy.
２．Specifications＆Performance
２．１ SpecificationsTable1
Model GD-200 GD-200C GD-200H
Application(Fluid) water、air、oil(kerosene、heavyoilA･B)
NominalSize 15A〜150A
InletPressure(MPa) 1.0orless 2.0orless
Reduced
Pressure(MPa)
15A〜80A：
(A)0.05〜0.25(B)0.26〜0.7
100A〜150A：
(A)0.05〜0.25(B)0.26〜0.5
15A〜50A：
(A)0.05〜0.25(B)0.26〜0.7(C)0.5〜1.0
65A、80A：
(A)0.05〜0.25(B)0.26〜0.7(C)0.5〜0.9
100A〜150A：
(A)0.05〜0.25(B)0.26〜0.5(C)0.5〜0.75
Min.Differential
Pressure(MPa) 0.05
Max.Pressure 
ReductionRatio  １０：１
Min.adjustable
flowCapacity Water:5L/min Air:10m3/h(normalstate)
Application
Temperature(℃) 5〜80 5〜60 5〜80
Coefficientof
viscosity(cSt) 600orless
Body DuctileCastIron
ValveSeat StainlessSteel
ValveDisc NBR
Materials
Diaphragm NBR
Connection JIS10KFFFlanged JIS20KRFFlanged
Surfacetreatment
15〜100A:
Electrodeposition
Paint
125〜150A:
Tarpaint(Black)or
Electrodeposition
Paint
Nylon11Coating
（Bothsides）
15〜100A:
ElectrodepositionPaint
125〜150A:
Tarpaint(Black)or
ElectrodepositionPaint

-2-■EPDT-096b■

Caution
Pleasecollatewithattachednameplateandspecificationoforderedmodel.
※Pleaseconsultfactoryincasetheydonotmatcheachother.

２．２ FlowRateCharacteristicsChart
Fig.1FlowRateCharacteristicsChart
※Off-setTable2
Nominalsize Springdivision Off-set
（A）、（B） Settingrange0.05〜0.7MPa Within0.05MPa
15A〜50A （C） Settingrange0.5〜1.0MPa Within0.11MPa
（A）、（B） Settingrange0.05〜0.7MPa Within0.05MPa
65A、80A （C） Settingrange0.5〜0.9MPa Within0.11MPa
（A）、（B） Settingrange0.05〜0.5MPa Within0.05MPa
100A （C） Settingrange0.5〜0.75MPa Within0.11MPa
（A） Settingrange0.05〜0.25MPa Within0.05MPa
（B） Settingrange0.26〜0.5MPa Within0.07MPa
125A〜150A （C） Settingrange0.5〜0.75MPa Within0.11MPa
２．３ PressureCharacteristicsChart
Fig.2PressureCharacteristicsChart
Theabovechartshowsthechangeinthereducedpressurewhentheinletpressure
ischangedintherangeof0.15〜1.0〜0.15MPawhereasthereducedpressureisset
at0.1MPaatinletpressureof0.15MPa.
Rate
d
fl
ow
Shut-off
p
ress.rise
Min. adjustable
ra
t
e
Flowrate
Reduced
Reduced
p
ress.

-3-■EPDT-096b■


３．Dimension&Weight
                               Table3

















Fig.3

※Thepartsshapediffersaccordingtothenominal
size.

Table4Dimension&Weight(mm)
Ｈ Ｈ1 Weight(kg)
Size Ｌ GD-200･200H GD-200C GD-200･200H GD-200C GD-200･200H GD-200C
15A 145 310 296 57 8.2 8.3
20A 150 310 296 57 8.2 8.3
25A 150 333 318 67 10.0 10.1
32A 195 397 398 76 17.3 17.4
40A 195 397 398 76 17.3 17.4
50A 195 415 412 81 19.2 19.3
65A 270 555 573 110 113 40.0 40.1
80A 270 582 598 125 128 43.7 43.8
100A 308 645 666 143 146 70.0 70.8
125A 380(384) 849 875 179 182 144.0(145.0) 144.1
150A 400(404) 918 930 204 207 173.0(175.0) 173.1
※MeasurementsshowninparenthesisareforGD-200H.
No. PartsName
1 Body
2 SpringChamber
3 ValveSeat
4 Valve
5 Spindle
6 Retainer
7 ORing
8 RetainerGuide
9 Diaphragm
10 SpringPlate
11 SpringPlate
12 AdjustingSpring
13 AdjustingScrew
14 LockNut
15 ConductorPipe
16 Bolt
17 Bolt
18 UNut
19 ORing
20 ORing
21 ORing
22 ORing

-4-■EPDT-096b■
４．Operation
Iftheadjustingscrew⑬isturnedright,the
diaphragm⑨willbedepressedwithaadjusting
spring ⑫  and valve disc ④  connected with
spindle⑤willopen.
Thefluidwhichflowedinfromtheinletside
carries out the action which pushes up
diaphragm⑨throughasensingpipeatthesame
timeitflowsintoaoutletsidethroughthe
valvedisc④upperpart.
Load to diaphragm⑨ balances with load of
adjustingspring⑫,anditadjusttheopening
of main valve to regulate the reducing
pressure.

Fig.4
Withclosingstopvalveattheoutletsideby
littlebylittle,theloadtodiaphragm⑨will
beincreasedbecauseofincreasinginreduced
pressure.  Increasing load to diaphragm⑨
overcomestheloadofadjustingspring⑫,and
thenclosesthemainvalve.







Fig.5

-5-■EPDT-096b■
５．NominalSizeSelectionMethod
５．１NominalSizeSelectionChart
<ForWater>
V：Flowrate（m３/h）
Fig.6
ExampleofSelection
Whentheinletpressure(P1)is0.5MPa,thereducedpressure(P2)is0.3MPaand
theflowrateis7m3/h,forinstance,thesizeofthepressurereducingvalveis
selectedasfollows.Findtheintersectionpoint(A)ofthedifferentialpressure
of0.2MPawiththeflowrateof7m3/h,thepoint(A)isbetweenlineofsize25A
and32A.
Chooselargersize32Aforapplication.
NominalSize
(A)
ΔP：DifferentialPress.（MPa）

-6-■EPDT-096b■
<ForAir>
Fig.7
ExampleofSelection
Whentheinletpressure(P1)is0.5MPa,thereducedpressure(P2)is0.3MPaandthe
flowrateis800Nm3/h,forinstance,thesizeofthepressurereducingvalveisselected
asfollows.Findtheintersectionpoint(A)oftheinletpressure(P1)0.5MPaand
reducedpressure(P2)0.3MPaandgostraightdownfromthepoint(A)tofindthe
intersection(B)crossingtheflowrateline.Thepoint(B)isbetweenlineof32A
and40A,andchooselargersize40Aforapplication.

-7-■EPDT-096b■
５．２SelectionFormulaforNominalSize 
・Cvvalue Table5
NominalSize 15A 20A 25A 32A 40A 50A 65A 80A 100A 125A 150A
Cvvalue 2.5 4 5 8 12 16 28 36 68 75 108
・CvValueCalculationFormula
<ForGas>
Incaseof 2
p
p1
2>   Incaseof 2
p
p1
2≤
()
()
21
VPPP Gt273
2940
Q
C+∆
+
=
()
1
VP2550
Gt273Q
C+ =
<ForLiquid>
P
GV365.0
CV∆
=
・ViscositycorrectionFormula
FindtheMax.Flowrate(V)whentheviscosityisignored.
G365.0
PCv
V⋅
∆⋅
=
AndfindtheviscosityindexofIv.
2
1
4
1
cst
VV
G
P
M
72780
I⎟
⎠
⎞
⎜
⎝
⎛∆
=
FindthevalueofKfromthevalueofIv,foundthroughtheaboveformula,
withtheviscositycorrectioncurve.ThecalculatedMax.flowratedivided
bythevalueofKisthecorrectedvalue.
CompensatedMax.flowrate Ｖ'＝Ｖ／Ｋ（m3/h）
ViscosityCorrectionCurve
P1:Inletpressure  [MPa･A]
P2:Reducedpressure [MPa･A]
ΔP:P1-P2      [MPa]
G:Specificgravity
(Gas:Specificgravityrelativetoair
Liquid:Specificgravityrelativeto
water)
V:Max.liquidflowrate[m3/h]
Q:Max.gasflowrate[m3/h(Normalstate)]
t:Temperature   [℃]
Cv:Cvvalueofthenominalsize
Ｉv:Viscosityindex
Mcst:Viscosity {cSt}

Fig.8

-8-■EPDT-096b■
６．Installation
６．１ExampleofPiping
●ForWater











Fig.9

●ForAir















Fig.10





-9-■EPDT-096b■
６．２Precautionsbeforeoperation
Caution
(１)Sinceitisweightthing,thisproductshoulduseliftingequipmentetc.,
andpleasesupportaproductcertainlyandinstallitinpiping.
※Thereisapossibilitythatitmaybeinjured,byfallofproduct.
(２)Donotdisassemblethevalveunreasonably.
※Disassemblingthevalveatyourdiscretionmayaffecttheoriginal
performance.
(３)Removeforeignmatterandscalesfromthelinesbeforeconnectingthevalve.
※Failuretodosomaypreventthevalvefromfunctioningcorrectly.
(４)Installastraineratthevalveinletside.
※Failuretodosomayhampercorrectpressurecontrol,whichaffectsthe
originalperformance.
※Bysunshineoratmospheretemperaturerise,thefluidinpipingcarries
outvolumeexpansion,failureofthevalveandtheexternalleakoffluid
occur,andthereisdangerofcircumferencecontamination.
(５)Installasafetyvalveatthevalveoutletsidesforalarms.
※Failuretodosopreventsproblemidentification,resultinginequipment
damage.
(６)Installapressuregaugeatboththeinletandoutletsidesofthevalve.
※Failuretodosomayhampercorrectpressureadjustment.
(７)Forgasapplication,installatraptotheinletsidesofthevalvetoprevent
drainageproblem.
※Failuretodosomayresultindrainageproblem,affectingtheoriginal
performance.
(８)Wheninstallingquickopenandclosevalves,suchasasolenoidvalve,secure
atleast3mfromthevalve.
※Failuretodosomayresultinmalfunctionordrasticallyshortened
servicelife.
(９)Whenreducingpressureintwostages,secureatleast3mbetweenthevalves.
※Failuretodosomayresultinmalfunction,affectingtheoriginal
performance.
(10)Installthevalveinproperdirectionofthefluidflow.
※Failuretodosomayaffecttheoriginalperformance.
(11)Donotapplyexcessiveload,torqueorvibrationtothevalve. 
※Doingsomayresultinmalfunctionordrasticallyshortenedservicelife.
(12)Pipescanbeinstalledeitherhorizontallyorverticallyexceptoverthe
sizeof100A.
(13)Thesafetyvalveshouldbesetasdescribedbelow.
Table6Safetyvalvesettingpressuretable
Settingpressureofareducingvalve(MPa) Settingpressureofasafetyvalve(MPa)
0.1orless Settingpressureofareducingvalve
+0.05ormore
0.11-0.4 Settingpressureofareducingvalve
+0.08ormore
0.41-0.6 Settingpressureofareducingvalve
+0.1ormore
0.61-0.8 Settingpressureofareducingvalve
+0.12ormore
0.8andabove Settingpressureofareducingvalve+15%

-10-■EPDT-096b■

(14)Ifthelargevalveisusedforgas,installareducertopreventexcessive
flowspeed.(Theflowspeedmadeinpipingsisappropriate,ifitis15m/s
orless.)
(15)Abovethecenterofthepipeline,besuretoreserveenoughspacelarger
thanH2(Fig.3).Pleaseseethefollowingtable.
Table7(mm)
NominalSize 15A 20A 25A 32A 40A 50A 65A 80A 100A 125A 150A
H2 500 500 500 650 650 650 800 800 1000 1200 1400
Fig.11

７．OperatingProcedure
７．１Precautionsforpressurereducingvalveoperation
 Warning
Donottouchthevalvedirectlywithbarehands.
※Doingso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.
※Failuretodosomaypreventthevalvefromfunctioningcorrectly.
(２)Whentheadjustpressure,slowlyturntheadjustingscrew
※ Incorrect adjustment may cause hunting, water hammer, etc.,
resultingindamagetothevalveandotherequipment.
(３)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.

-11-■EPDT-096b■

７．２AdjustmentProcedure
 Caution
(１)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valvesatbothsidesofthepressurereducingvalve,and
thoroughlypurgethesystemthroughtheby-passline,withtheby-passvalve
openingadjustedsothatthesafetyreliefvalveisnotactivated.When
completed,besuretoclosetheby-passvalve.
(２)Slowlyopentheinletstopvalve,thenopentheoutletstopvalveslightly,
allowingatrickletobedischarged.
(３)Loosenthelocknut⑭,andslowlyturntheadjustingscrew⑬(clockwiseto
increase,counterclockwisetoreduce)whileobservingthepressuregaugeon
theoutletside.
(４)Slowlyopentheoutletstopvalvetoitsfull-openposition.
(５)Aftertheadjustment,tightenthelocknut⑭.
(６)Incaseofsecondarypressureforsize65Ato150Aisunstablebecauseofan
airobstructionoretc.,adjustopeningofneedlevalveatdetectingpipe.

Fig.12
Adjustingscrew⑬
Locknut⑭
Reducedpressuregoesdown．
Reducedpressuregoesup．

-12-■EPDT-096b■
８．MaintenanceProcedure
８．１Troubleshooting
Problem Causes Solutions
Pressuredoesnot
risetodesired
level.
1.Incorrectpressureisbeing
used.
2.Theconductorpipe⑮ isclogged
withforeignmatter.
3.Nominalsizeistoosmallfor
thesespecifications.
4.Incorrectadjustment.




5.Strainerisclogged.
6.Pressuregaugemalfunction.
1.Correctthepressurebeingused.
(Refertothe“Specifications”.)
2.Disassembleandcleantheconductor
pipe.
3.Replacewiththecorrectnominal
 sizeditem.
4.Re-adjustaccordingtothe
adjustmentprocedure.
(Refertothe“Adjustment
Procedure”.)
5.Disassembleandclean.
6.Replacethepressuregauge.
Reducedpressure
exceedsprescribed
level.
1.Foreignmatterisembeddedin
thevalve④and/orvalveseat
③,orelsescratchesexist.
3.By-passvalveisleaking.
1.Disassembleandclean.If
scratchesexist,replacethem.
3.Repairorreplacethevalve.
Externalleakage Diaphragm⑨isbroken. ReplaceDiaphragm⑨
Abnormalnoiseis
heard. 1.Nominalsizeistoolargefor thesespecifications.
2.Pressurereductionratiois 
  toolarge.
3.Airproblemiscaused.(Liquid
use)
4.AnabruptOPEN/CLOSEvalveis
  locatedtooclosetothe
pressurereducingvalve.
1.Replacewiththecorrectnominal
  sizeditem.
2.Useatwo-stagereduction.
  (Refertothe“Specifications”.)
3.Installatrap.

4.Allowasmuchdistanceas
  possiblebetweenthevalves.

※Foreignmatterandscalesinpipemaycausemostofproblemsofpressure
reducingvalve.Becarefulsufficientlytoforeignmatterin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particularsbefore
abovetroubleshooting.

-13-■EPDT-096b■
８．２Precautionsduringdisassembly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 ) Perform periodical inspection to maintain product functions and
performance.
※ General users shall request countermeasures to installers or
maintenancecompanies.
(２)Thepressurereducingvalveshallbedisassembledandinspectedby
qualifiedpersons.
(３)Rubberpartsandcomponentsshownbelowareconsumables. Notethatthe
lifeexpectancydependsontheconditionsunderwhichtheyareused.
Table8
Serviceablelife Partsname/number
3years Valve○
4 、Oring○ 7 、Diaphragm○ 9

5years Oring○
19 ○ 20 ○ 21 ○ 22 

※Forcirclednumbers,referto３．Dimension&Weight.
８．３Disassembly
(１)Releavetheinternalpressurecompletely,andmakesureofzeropressure.
(２)Slightlyloosenthelocknut⑭andturntheadjustingscrew⑬counter
clockwisetorelievetheadjustingspring⑫(Unloadthespring).
(３)Removethehexagonbolt⑰fromthespringchamber②,thenremovethespring
chamber②,andtakeouttheadjustingspring⑫andthespringplate⑩.
(４)Toremovethediaphragm⑨,fixthespindle⑤andremovetheUnut⑱.
(５)Toremovetheretainer⑥,loosenandremovetheretainerguideclampingbolt
⑯andpulltheretainerguide⑧.
Removeitbythebellowmethod（Fig.13,Fig.14）whenitisdifficulttoremove
theretainerguide⑧.
(６)Toremovethevalveseat③,pullthespindle⑤.
(７)Fixtwoplanarsectionsatspindle⑤andloosenUnutforspindletoremove
it,thenthevalvecanbedismounted.


-14-■EPDT-096b■
NominalSize15A
〜 50A
Toremovetheretainerguide⑧easily,installthespringplate⑪andUnut
⑱tospindle⑤againandpullthespringplate⑪.（Fig.4）
Fig.13
NominalSize65A 〜 100A
Toremovetheretainerguide⑧easily,screwtheretainerguideclampingbolt
⑯toretainerguide⑧andpullit.(Fig.5)

Fig.14
８．４Precautionsduringdisassembly
(１)Makesurethatthediaphragm⑨,thevalveseat③,andthevalve④haveno
scratches.
(２)ApplythesilicongreasetotheO-Ring⑦afterconfirmwhetherthereareany
flawontheO-Ring⑦.
(３)Installthespringchamber②aftertheconfirmwhethertheborderofdiaphragm
⑨isfittedwiththegrooveofbody①.
(４)Forsize15Ato50A,assemblespringchamber②afterconfirmingtheouter
circumferenceofdiaphragm⑨interlaceswithgrooveatthebody①.
Forsize65Ato150AofGD-200H,confirmtheboltholeofdiaphragm⑨fitto
boltholeatbody①.
TighteningtorqueofUnut⑱fordiaphragmandhexagonbolt⑰forspringchamber
aredescribedbelow. Table9
Nominalsize 65A、80A 100A 125A、150A
TighteningtorqueofUnut⑱(N-m) 60 60 280
Tighteningtorqueofhexagonbolt⑰(N-m) 20 40 50


Unut
⑱

S
p
rin
g

p
late
⑪

Spindle
⑤
Retainerguideclampingbolt⑯
Retainerguide⑧

-15-■EPDT-096b■
８．５Explodeddrawing

・Partswiththe※areconsumable.
Pleasecontactusforpurchaseoftheseconsumableparts.

2009.9
PDD-046c
Warranty Information
1. Limited warranty
This product has been manufactured using highly-advanced techniques and subjected to
strict quality control. Please be sure to use the product in accordance with instructions on
the manual and the label attached to it.
Yoshitake warrants the product to be free from any defects in material and workmanship
under normal usage for a period of one year from the date of receipt by the original user, but
no longer than 24 months from the date of shipment from Yoshitake’s factory.
2. Parts supply after product discontinuation
This product may be subject to discontinuation or change for 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 due to any of below:
(1) Valve seat leakage or malfunction caused by foreign substances inside piping.
(2) Improper handling or misuse.
(3) Improper supply conditions such as abnormal water pressure/quality.
(4) Water scale or freezing.
(5) Trouble with power/air supply.
(6) Any alteration made by other than Yoshitake.
(7) Use under severe conditions deviating from the design specifications.
(8) Fire, flood, earthquake, thunder and other natural disasters.
(9) Consumable parts such as O-ring, gasket, diaphragm and etc.
Yoshitake is not liable for any damage or loss caused by malfunction or defect of the product.
INTERNATIONAL DEPT.
7-3, Futanocho, Mizuho, Nagoya, Aichi, 467-0861, Japan
Phone: [phone] Fax: [phone]
E-mail: [email protected]
