Farr KT5500 - Torque Measurement; Basic Torque Measurement

KT5500 5-
1
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2
” Tong & CLInCHER® BaCKup
SECTIon ConTEnTS
6.1
TECHnICaL ManuaL
A. BASIC TORQUE MEASUREMENT
Basictorquemeasurementsareperformedusingasimplehydraulicmeasurementsystem.Ahydraulicloadcellconnectstoacali-
bratedtorquegaugethroughareinforcedflexiblehydraulichose.Thetorquegaugeisfactory-calibratedtodisplayaccuratetorque
measurementsforatongortongandbackupassemblywithaparticulararmlength.Thearmlengthisameasurementfromthecentre
ofthepipeorcasingtothecentreoftheforcebeingappliedtotheloadcell.
Twoloadcelloptionsareavailable.Atensionloadcellistypicallyusedwithasuspendedstand-alonetong.Thisapplicationrequires
thattheload cell beattachedto the rearofthe tong aspartofthe restraintlinethatopposes theforcegeneratedwhen thetong
makesuporbreaksoutajoint.Acompressionloadcellisusedinatongandbackupassembly,andistypicallylocatedontherearof
thebackupbetweenthebackupandastationaryframe.Theloadcellmustbelocatedinthecentreofthecompressionforcevector
generatedbetweenthebackupandtheframe.
Hydraulicforcegeneratedbyaloadcellistransmittedtothetorquegaugeviaareinforcedflexiblehydraulicline.Thehydraulicforce
isdisplayedastorqueinunitsofFt.-Lbs.Thetorquegaugehasared“peaktorque”indicatorthattrackswiththetorquegaugeneedle
tothepoint of highesttorque,andremains at thepointofhighest torqueuntilmanuallyreset. Note thateverymodelof tongand
tongandbackupassemblyhasauniquearmlength,andthetorquegaugemustbecalibratedforthatarmlength.Torquegauges
thatarenotcalibratedforthearmlengthofthetoolinservicewillnotdisplaycorrecttorque.Toensurecorrecttorquemeasurement,
ensurethearmlengthor“handle”asdisplayedonyourtorquegaugematchesthearmlengthofthetoolinserviceaslistedonthe
specificationspageofthetechnicalmanual.
Theimagesonthispageareforillustrationpurposesonlyandmaynotaccuratelyrepresentthetorquegaugeandloadcellthathave
beensuppliedwithyourequipment.
torque gAuge (for
illustrAtion purposes only)
compression loAD cell
THE IMAGES DISPLAYED ARE SUPPLIED FOR ILLUSTRATION PURPOSES ONLY
TORQUE GAUGES AND LOAD CELLS ARE FACTORY-SUPPLIED SUPPLIED AS MATCHED CALI-
BRATED PAIRS. IF REPLACING EITHER COMPONENT THE LOAD CELL AND TORQUE GAUGE
MUST BE RETURNED TO THE FACTORY FOR RE-CALIBRATION BEFORE PLACED INTO SERVICE.
Torque gauges and load cells are supplied asa matched calibrated pair. Substituting one or theother will render the calibration
inaccurateeveniftheactualmodel numbers appeartobeidentical.Theserialnumbersof matching loadcellandtorquegauges
areclearlyidentifiedonthecalibrationcertificate.Shouldyoususpecttheaccuracyofyourtorquemeasurements,orwishtoreplace
eithercomponentthepairshouldbereturnedtothefactoryforre-calibrationbeforeplacingintoservice.
tension loAD cell
ToRquE MEaSuREMEnT