Transcription of C Boost 111-122 - Fairchild Industrial Products
1 DModel21 Model21 Relay8 1/27 13/32 MOUNTING SURFACEMOUNTING HOLES128800-334-8422 Features Venturiasp irat ion compen sates for down -st ream pres sur e loss es Optionalinpu t and output biasingallowsversati lity in ap plic atio ns Adjustablefrom 30:1 divid ing ratio to 1:30multi plyi ng rati o assur es infi nite pressu readjustments Floatingseal ring isolatescon trol cha mberwhich increasessta bility by red ucing effectof high flow s. Panel or Line Mou ntingOperating PrinciplesThe Model 21 co nsists of a signal chamb erlever arm, a Mo del 20 output valve body, andpi vot assem bl y for lever arm adjustment. Therati o of outp ut pr ess ure to signal pressureisinfi ni tely adjus table.
2 The adjustment ran geper mits signa l ampl ificatio n of 1:30 or sign alreductionof 30: 1 by rotationof the ratioadjus tment kno signal pre ssu re ac ting on the signa lchamberdia phra gm trans mits a forcethro ugh a lever to the cont rol di aph ragm ,thus setti ng out pu t pres sure. Th e leverfulcrumis adj ust pu t pressureis a functionof signa lpressuretimes the rat io of lever arm lengt hson ei ther side of the may beintr oducedby me ans of the set Model 21D is av ailable with bo th inp utand output adjus table bia s. Maximuminpu tbi as is 3 psi g, wit h a max imum output bias of9 psig. The ba sic mathematical expressionfor the bias in this relay is:Po = (Ps-K1)R+K2, wherePo = Outputpre ss urePs = Input sign alR = Ratio of se tti ngK1= Input bias , (- ) onlyK2 = Outputbias , (+) only("D" OPTION ONLY)("D" OPTIONONLY)KNOBASSEMBLYOUTPUT BIASSPRINGSU PPL YOUTLETOUTPUTBOOSTERSIGNAL CHAMBERDIAPHRAGMPIVOTASSE MBL YLEVER ARMFULCRU MDModel21 Model21 RelayTechni cal Information129800-334-8422Ca talo g Infor mationInstallationA servicekit is availablefor th e Mode l 21.
3 Re fer to theFairchildModel21 RelayIn sta llat ion,Oper ationandMaintenanceInstructions,IS-1 000 002 = 20 psigSetpoint = 100 psigSupply Pressure = 150 psigAir Flow, SCFMO utputPressure PSIGFlow CharacteristicsFairchild Model 21312 Specifica tionsFl ow Cap aci ty40 SCF M (68 m3/HR ) 100 psig, [ BAR], (7 00 kPa )supply , 20 psig, [1. 5 BAR], (15 0 kPa)Exhaust SCFM ( m3/HR ) (downstream pre ssur e 5 psig,[.35 BAR] , (35 kPa) abo ve set pr essure )Supply Pressu re25 0 psig, [ BAR ], (1 70 0 kPa) MaximumSupply Pressu re Ef fec tLe ss th an .1 psig, [.0 07 BAR], (.7 kPa) for 100 psig,[ BAR] , (700 kPa) cha ngeSignal or Output Pre ss ur e15 0 psig, [ BAR ], (1 00 0 kPa) MaximumRati oRa nge30 :1 through1: 30 (sign al pr essu re : output pre ssure)Operating Pressure (minim um ) psig, [ BAR], ( kPa ) ( cm) Wate r Colu mnAmbient Temperat ur eLimit s-40 F to +200 F,(-40 C to +93.)
4 3 C)Ma teria ls of Constr uc tio nBody and .. Alumin umTrim .. StainlessSt eel, Br ass, and Zin e Plate d SteelDi aph ragms .. Buna N and DacronLe ver and ..Harde ned Stee lCatalo g Number2 1 3 1 Pipe Siz e1/4"NPT..23/8"NPT..3 OptionsBias1.. JTamper Proof..TBSPT (Tapered)..U1 MaximumInput Bias: -3 psig, [ BAR], (-20 kPa),Maxi mum Output Bia s: psig, [ BAR], (6 0 kPa)
