b' Shear Pin HubThis device uses a hub thatDualPressureGauges Oneofthemostattachesbetweenthemotorandtheanchor commonwaystodeterminemotoroutputshaft.Maximum shaft torsion is determined torqueistomeasurethedifferencebetweenby inserting a number of shear pins between the input pressure and output pressure acrosstheflangesofthehub.Eachpinusually the motor.When using two gauges installedrepresents500ft-lbs.Baseduponthetotal one on each port of the gear motor, the actualnumberofpinsused,onecanrestrictthe pressure drop across the motor is monitored.maximumtorsionthatcanbeappliedtothe Thisisatheoreticalrepresentationoftheshaft.When the desired torsion is reached, the amount of hydraulic energy that was used bypinsshearandthehubnolongertransmits themotor.Oncethepressuredifferentialistorsiontothehelicalanchorshaft.Forthis determined,theoutputshafttorquecanbedevice to accurately predict ultimate capacity, estimatedfrommotorperformancedatathesoilintowhichthescrewanchoris provided by each motor manufacturer.installedmustbehomogeneousandwithno Itisespeciallyimportanttohavethegaugesobstructions.Theshearpinhub,bynature, calibratedregularly.Gaugescanbecometendstooverestimatetheshafttorsion.If, damaged and rendered inaccurate in the field.during installation, the helical plates encounteranobstructionorsomethingthatcausesaStrain Gauge Monitor (Torque Transducer)spikeintheshafttorque,theshear pins Thisdeviceprovidesadirectdisplayofbecome deformed and weakened.In addition, installation torque being applied to the shaft; itifthetargetstratumrapidlybecomesvery also provides a recorded history of the shaftdense,theshearpinsmaybreakbeforeall torsion through the entire depth of installation.plates have been properly embedded.This is This system consists of three parts; a Torqueespeciallyimportantintensionapplications AnalyzerRotorinstalledontheflangedwherethedesiredshafttorsionshouldbe coupling between the motor and anchor shaft,averaged over a distance of at least three feet aTorqueAnalyzerPDAindicatorandabeforeterminatingtheinstallation.Earth battery charger.Contact Products does not endorse the shear Theunitisextremelyruggedandidealforpin hub and considers it a less accurate way to fieldbasedapplications.Thestraingaugemeasure shaft torsion. monitor measures the torque applied between SinglePressureGauge Manyoperators two flanges located between the motor outputinstall a single pressure gauge at the inlet to shaft and the helical anchor shaft.This data isthe hydraulic gear motor.This is a dangerous transmittedtoaPDAreadoutdeviceforpracticeand notrecommendedbecausein displayandlogging.Thismethodofnearlyeveryhydraulicsystemthereisback measuringthetorqueappliedishighlypressure.Thisbackpressurerepresents accurate(+/-0.25%).Thetorquesensorisenergy that enters the gear motor, but is not built into the housing of the flanges and theused by the motor.The back pressure simply dataistransferredbyawirelesstransmittercauses the oil to flow back into the system and fitted into the housing.to the reservoir.Typically, back pressures can The torque datacapturedbythePDAisrange from 200 to 500 psi, and in some cases recorded as a text file that can be viewed orhigher. downloadedtoanycomputersoftwareforThedangerinusingasinglegaugeto further analysis, such as Microsoft Excel.estimateshafttorsionisthattheback This unit is the most accurate and rapid way topressure is unknown.As a result, the shaft monitorandrecordinstallationtorque.Itistorsion on the shaft is overestimated, which highly recommended.resultsinananchorcapacitypredictionthat is overstated. EARTH CONTACTAnchorsinstalledwithasinglegauge PRODUCTSsystem,ingeneral,willnotproduce the Designed andactual capacity as expected and could fail. Engineered to PerformECP Technical Design Manual - Installation & Testing2021 Earth Contact Products, L.L.C.2021-09 Chapter 4 - Page 63 All rights reserved'