Siemens VGD20.253U - Page 3

VGDSeriesDoubleValves TechnicalInstructions
 DocumentNumberCC1N7631us
 November08,2017
SiemensAGBuildingTechnologiesDivision Page 3
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Application
AllVGDxx.xxxUvalvescanbecombinedwithanySKPxx.xxxUseriesactuator.Theactuator
canbemountedwhilethevalveisinstalledandunderpressure.

SKPxx.xxxUregulatingactuatorsareapplicableforbothlowandhighsupplygaspressure
applications,eliminatingexcessiveregulatorinventories.Maximumpressureratingsvary
withvalvesize(seeTable
2).

AllVGDxx.xxxUvalvesperformthesefunctionsincombinationwitheachofthefollowing
actuators:

SKP15.xxxU Safetyshut‐off
SKP25.xxxU Safetyshut‐offandconstantpressureregulationorzerogovernor
SKP55.xxxU Safetyshut‐off,pressureregulationanddifferentialpressureair‐gasratio
control
SKP75.xxxU Safetyshut‐off,pressureregulationand
adjustableair/gasratiocontrol

Sincemorethanonefunctioncanbeperformedbyasinglevalve,fewercomponentsand
fittingsarerequired‐significantly reducingboththesizeandweightofthegastrain.In
addition,smallerdiametergasvalvescanbeused.Fordetailsonvalvesizingseetheflow
chart(figure3).


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CAUTION:
DonotoversizevalvesequippedwitharegulatingSKP2x.xxxU/SKP5x.xxxU/
SKP7x.xxxUactuator.Oversizingmaylimitturndownandcouldcauseoscillations.