The document describes the operation of a rotary screw compressor used on a T450WS drilling rig. It contains the following key details: - The compressor uses a two-stage, oil-flooded rotary screw design to compress air. It has precision-matched male and female rotors that mesh to reduce cavity volume and increase pressure. - Compressed air and oil mixtures from each stage are directed to the air-oil tank for separation before the air is used for drilling operations. The oil is recirculated for cooling and lubrication. - Controls include a clutch, pressure selector valve, and load/unload selector valve to modulate compressor capacity based on air demand from drilling tools. Proper

1. T450WS 7-1 Section7: CompressorGeneral DescriptionThe T450WS usesa Sullairtwo-stage
compressor.The Sullaircompressorisatwo-stage,positive-displacement,oil-floodedrotaryscrew
machine usingmeshinghelical rotorstoproduce compressedair.The rotaryscrewsare showninFigure
7-1. It is builtforeffective workingpressuresof upto350 psig(24.1 bar). Figure 7-1. Rotary Screw The
firstand secondcompressorstagesare individuallyboltedtothe gearhousing.Engine poweris
transmittedthroughagear setin the gearhousingto the individual stages.The drivenpiniongearsare
mountedonthe male rotor shaftof eachstage.Each stage hasprecisionmatchedrotorpairs:a male
rotor whichdrivesafemale rotorona cushionof air andoil.All rotorsare supportedbyhighcapacity
antifrictionbearings.The rotorsare an asymmetricdesignthatprovide bettersealingandincreased
volumetricairdelivery,asshowninFigure 7-2.Figure 7-2. RotorClearance andSealingStrip
161. Section7: CompressorOperation&Maintenance Manual T450WS7-2 CompressionPrinciple
Compressionisaccomplishedbymeshingrotors. Inthe firststage of the compressioncycle,the rotors
are notmeshedastheypass the air intake port.The air isdrawn intothe cavitybetweenthe male rotor
lobesandthe female rotorgrooves,shownin#1 of Figure 7-3. Whenthe rotorspass the intake port
cutoff,airis trappedinthe interlobe cavityandflowsaxiallywiththe meshingrotors,asshownin#2 of
Figure 7-3. Asmeshingcontinues,more of the male rotorlobe entersthe female rotorgroove,asshown
in#3 of Figure 7-3. The interlobe volume isreducedandpressure increases,asshownin#4 of Figure 7-
3. Figure 7-3. CompressorAirDeliverySimultaneously,oil isinjectedintothe compressioncavityto
remove the compressionheat,lubricate the rotor,andseal the internal clearances.Volume reduction
and a pressure increase continueuntil the air/oil mixture trappedinthe interlobe cavitybythe rotors
passesthe discharge portand isreleased.The dischargedair/oil mixturefromthe firststage isdirected
to the inletof the secondstage withnointercoolingoroil separation.The secondstage continuesthe air
compressiontoitsfinal pressure.The dischargedair/oilmixture fromthe secondstage isdirectedtothe
air-oil tankforoil separationandstorage.The air andoil flow isshowninFigure 7-4.
162. Section7: CompressorOperation&Maintenance Manual T450WS 7-3 Figure 7-4. Airand Oil Flow
Engine The compressorisdrivenbya watercooleddiesel engineof sufficientpowertodrive the air
compressor,the righydraulics,andthe coolingfan.A diesel engine manual issuppliedwiththe drillrig.
Engine-CompressorCouplingA drive couplingcouplesthe engine tothe compressor.The drive coupling
isshownin Figure 7-5.Figure 7-5. Drive Coupling(Left) andClutchDrive RingwithAdapter(Right) The
engine iscoupledtothe aircompressorthrougha 14 inch,double-plate,andover-centeradjustable
clutch.The clutchisdisengagedtostartor runthe
163. Section7: CompressorOperation&Maintenance Manual T450WS7-4 engine withoutthe
compressorload.Clutchadjustmentismade throughaservice hole atthe topof the clutch housing,as
showninFigure 7-6. The clutch’sworkingtorque issufficientenoughtoprovide longplate lifeunder
normal workingconditionsaslongasthe clutch isproperlyadjustedandlubricated.Donotengage or
disengage the clutchwhile the engineisrunning.Also,donotattemptto adjustthe clutchwhile itis
running.Damage and/orseriousinjurywill occur.Figure 7-6.ClutchAdjustmentEngagingand
Disengagingthe ClutchThe clutchisengagedanddisengagedusingaclutchhandle inthe clutch lever
locatedbeneaththe air-oil tank,showninFigure7-7.The clutch handle issuppliedwiththe rigandis
locatedinthe tool box.Figure 7-7. ClutchLever(Top) andWrench (Bottom) Todisengage the clutch,use
the clutch handle toturn the clutchleverclockwise.Toengage the clutch,use the clutchhandle toturn
the clutch levercounterclockwise.Donotengage or disengage the clutchwhilethe engineisrunning.

2. 164. Section7: CompressorOperation&Maintenance Manual T450WS 7-5 Oil SeparationThe air-oil
tank,showninFigure 7-8, is a pressure vesselthatreceivedthe air/oil mixture fromthe compressor.The
air/oil tankalsocontainsan air/oil separator.Figure 7-8.CompressorAir-OilTankAsthe air/oil mixture
fromthe discharge of the compressorentersthe air-oil tank,itimpinges(strikes) uponabaffle and
changesdirection.Also,the mixture velocityisdrasticallyreduced.Thiscausesmostof the oil to fall to
the bottomof the tank.The small amountof remainingoil inmistformiscarriedalongwiththe air and
isremovedbythe oil separatorelement.Oilthatpassesthroughthe separatoriscollectedbymeansof a
separatordrain(scavenger) lineandreturnedtothe compressorinlet.AirFlow The Compressor
Pressure LoadSelectorisusedtocontrol the compressedairflow inthe compressor.The airpressure is
regulatedbydifferential pilotvalves(225– unloaded,350 – high).Atmosphericairentersthe aircleaner
assemblyandpassesthroughthe suctioninletbutterfly(unloader) valve,showninFigure 7-9,tothe low
pressure stage of the compressor.The butterflyvalveisopenwhennormal compressionoccurs.The
butterflyvalve isclosedwhenmaximumcompressionhasbeenreached.
165. Section7: CompressorOperation&Maintenance Manual T450WS7-6 Figure 7-9. ButterflyValve
(UnloadedPosition) Aftercompressionandoil separation,the compressedairleavesthe air-oiltank
througha combination minimumpressure/checkvalve foruse inthe drillingoperation,asshownin
Figure 7-10. Figure 7-10. SchrammMinimumPressure ValveOil Flow Oil isforcedbythe airpressure
fromthe oil sumpof the air-oil tankto the thermostaticvalve,showninFigure 7-11,where the oil is
eitherflowedthroughthe oil coolerorbypassedaroundthe oil coolerdependingonthe oil
temperature.
166. Section7: CompressorOperation&Maintenance Manual T450WS 7-7 Figure 7-11. Thermal Valve
The oil thenflowsthroughthe oil filtertothe oil stopvalve,showninFigure 7-12,and isdistributedto
variousportsin the compressorforcoolingandlubrication.Lubricationof the compressorbearingsand
the drive gearset isaccomplishedthroughinternal passagewayswithinthe compressor.All oilis
eventuallyinjectedintothe compressorandisdischargedtothe air-oil tankforseparationand
recirculation.Figure 7-12.Oil StopValve AirandPressure Control SystemThe compressorisprovided
withan automaticcontrol system. The systemcontrolsthe compressor’sairdeliverytomatchthe air
consumptionof the items(tools,etc.) thatare connectedtothe airoutletvalve from100% to 0% of the
compressor’sratedoutput.Airpressure iscontrolledbythe “COMPRESSORPRESSURE LOADSELECTOR”
valve andthe “COMPRESSOR LOAD/UNLOADSELECTOR” valve.Thiscapacitycontrol isaccomplishedby
throttling(openingandclosing) the inletof the low pressure stage.The airdemandcanvaryand the
inletbutterfly(unloader) valve will modulateproportionallytopermitthe necessaryoutputcapacity.
Whenair isno longerrequired,the butterflyvalve closes.The closedbutterflyvalve preventsfurtherair
compression.Assoonasthe air demandreturns,the butterflyvalveopensandresumescompression.
167. Section7: CompressorOperation&Maintenance Manual T450WS7-8 CompressorOperationIf
addingcompressoroil tothe air-oil tank,depressurize the system.Seriousinjuryordeathcan occur.
IntroductionEverycompressorsystemisoperatedandthoroughlytested.Allcontrolsare adjustedat
the factory before shipping.However,regardlessof the care takenat the factory, some damage could
occur duringshipment.Inspectthe unitcarefullyforpossibledamage beforeoperation.Also,watchthe
compressorforany signof a possible malfunctionduringthe firstfew hoursof operation.Readall
instructionsbefore operatingthe compressor.PreparationforStartUp NOTE: Numberswithinbrackets(
) refertocalloutsfromthe systemdiagram(Figure 7-19) on page 7-15. Performthe followingstepsprior
to startingthe compressor.1. Checkthe engine radiatorcoolantlevel,engine oillevel,hydraulicoil,and

3. compressoroil level inthe air-oil tank(15) to ensure theyare notlow.2. For first-time compressorstart-
up or if the compressorhas beenoutof service forseveral months,pour1to 1½ quarts(0.94 to 1.42
liters) of syntheticcompressoroil (PolyalphaolefinPAO) directlyintothe compressorinlet,shownin
Figure 7-13. Figure 7-13. CompressorInlet
168. Section7: CompressorOperation&Maintenance Manual T450WS 7-9 To pour oil intothe
compressorinlet:a) Take the elbowoff the hose.b) Place afunnel intothe hose.c) Addthe oil through
the funnel intothe hose.d) Reattachthe hose to the compressorusingthe elbow.3.Disengage the
clutch(2), showninFigure 7-8, if applicable,foreasierengine starting.4.Drainanywater fromthe air-
oil tank(15), showninFigure 7-14, andcontrol air line filter(4) throughvalvesprovidedatthe bottoms
of theirreservoirs.Figure 7-14.Air-Oil TankDrainLocation(Left) andValve (Right)5.Close the mainair
valve (26) in the air outletline of the air-oil tank(15) usingthe “AIRVALVE”control on the control panel.
6. Set the “COMPRESSORPRESSURE LOAD SELECTOR” valve (9) incontrol panel tothe LO-PR(Low
Pressure) position.Setthe “COMPRESSORLOAD/UNLOADSELECTOR”to the “UNLOAD” position.7.Set
“AIR GAUGE SELECTOR” valve (27) in the control panel tothe “SUMP” position.Normal Start-UpNOTE:
Numberswithinbrackets( ) refertocalloutsfromthe SystemDiagram(Figure 7-19) on page 7-15.
Compressorstart-upisbaseduponenvironmentaltemperatures.Normal compressorstart-upshouldbe
performedwhenthe weatherisabove 32 °F (0 °C).For Normal weatherstart-up- above 32 °F (0 °C): 1. If
the engine andcompressorare connectedwithaclutch:a) Disengage the clutch(2),as describedin
Engagingand Disengagingthe Clutchonpage 7-4. b) Start the engine (3) usingthe normal “START”
controlson the control panel.Letitwarm up fora few minutes.
169. Section7: CompressorOperation&Maintenance Manual T450WS7-10 c) Stopthe engine (3) by
usingthe “NORMAL STOP”controlson the control panel,andengage the clutch(2). Do not engage
clutchwith engine running.Seriouscompressordamage willoccur.d) Restartthe engine (3) usingthe
normal “START” controlson the control panel.2. If the engine andcompressorare directlyconnected,
thenstart the engine usingthe normal “START”controlson the control panel.3.The sumpair pressure
shouldbuilduptothe minimumpressure of 200 psig(13.8 bar).Increase the engine speedto1500/1600
rpm by turningthe “ENGINERPM” knobon the control panel.Letthe engine andcompressorwarmup
for a fewminutes.Watchthe discharge temperatureonthe compressortemperaturegauge (12) inthe
control panel.Donot allowtemperaturestoexceed250 °F (120 °C).If temperaturesexceed250 °F (120
°C),shut downthe rig,wait30 minutes,checkthe compressoroil,add compressoroil tothe rigif
necessary,andtry again.4. Increase the engine speedtothe ratedspeedbyturningthe “ENGINERPM”
knob.Turn the “COMPRESSOR PRESSURE LOADSELECTOR” valve (9) inthe control panel to the “RUN”
position.The compressorisreadyforfull-loadoperation.The engine will runupto1800 rpm. Cold
WeatherStart-UpCompressorstart-upisbaseduponenvironmental temperatures.Coldstart
compressorstart-upshouldbe performedwhenthe weatherisbelow 32°F (0 °C). Forcold weather start
up - below32 °F (0 °C):1. Disengage the clutch(2),as describedinEngagingandDisengagingthe Clutch
on page 7-4. 2. Start the engine inaccordance withthe engine manufacturer’sinstructionsforcold
weatherstart-up.Consultthe engine manufacturer’soperator’smanual formore information.3.Stop
the engine (3) byusingthe “NORMAL STOP” controlsonthe control panel,andengage the clutch(2).Do
not engage the clutchwiththe engine running.Seriouscompressordamage will occur.4. Restart the
engine (3) usingthe normal “START”controlson the control panel.5. The sump airpressure shouldbuild
up to the minimumpressure of 200 psig(13.8 bar).Immediatelyturnthe “COMPRESSORPRESSURE
LOAD

4. 170. Section7: CompressorOperation&Maintenance Manual T450WS 7-11 SELECTOR” valve (9) onthe
control panel to the “RUN” position,increase enginespeedto1500/1600 rpm usingthe “ENGINERPM”
knob,and throttle the mainairvalve (26) usingthe “AIR VALVE”controlson the control panel toholda
sumpair pressure of 200 psig(13.8 bar).Let the engine andcompressorwarmup (feel the bottomof
air-oil tank).Watchthe discharge temperature onthe “COMPTEMP” gauge (12) in the control panel.Do
not allowtemperaturestoexceed250°F (120 °C). If temperaturesexceed250°F (120 °C),shutdownthe
rig,wait30 minutes,checkthe compressoroil level,addcompressoroil tothe rigif necessary,andtry
again.6. Once the compressoroil iswarm, increase the engine speedbyturningthe “ENGINERPM”
knobto the rated speed.The compressorisreadyforfull-loadoperation.ShutDownNOTE:Numbers
withinbrackets( ) referto calloutsfromthe SystemDiagram(Figure 7-19) on page 7-15. 1. Slowlyopen
the mainair valve (26) to exhaustthe airfromthe air-oil tank(15) to the atmosphere.2.Whenthe sump
air pressure dropstobelow225 psig(15.5 bar),turn the “COMPRESSORPRESSURE LOAD SELECTOR”
valve (9) inthe control panel tothe “225” positionandclose the mainairvalve (26) by usingthe Air
Valve control.Setthe “COMPRESSORLOAD/UNLOADSELECTOR” to the “UNLOAD” position.Donotturn
the “COPRESSORLOAD LOAD/UNLOADSTART& STOPSELECTOR” fromthe “LOAD” to the “UNLOAD”
positionwhenthere ismore than225 psig(15.5 bar) sumpair pressure inthe system. Damage can occur
to the control system.3. Slowlyreduce the engine speedto1400 rpm usingthe “ENGINE RPM” knob.4.
Once the compressorunloads(the inletbutterflyvalve (10) closes),reduce the engine speedto1200
RPM. 5. Afterthe compressortemperaturedropsbelow 180°F (82.2 °C) Shutoff the engine (3) usingthe
“NORMAL STOP”controlson the control panel.6. The systemblow downvalve (22),showninFigure 7-
15, shouldimmediatelyreleaseairfromair-oil tank(15) reducingthe sumpair pressure to0 psig (0 bar).
171. Section7: CompressorOperation&Maintenance Manual T450WS7-12 Figure 7-15. SystemBlow
DownValve CompressorSystemControlsandComponentsSettingthe CompressorUnloadingControls
NOTE: Numberswithinbrackets( ) refertocalloutsfromthe systemdiagram(Figure 7-19) on page 7-15.
Use properhearingprotection.Notwearingproperhearingprotectioncancause immediatepainif the
noise istooloud,butit can also resultinlong-termhearinglossif the noise isnotloudenough tobe
painful.Whensettingthe CompressorUnloadingControls,openandclose the mainairvalve (27) once
or twice to ensure the adjustmentsare consistentandrepeatable.1.Follow the compressorstart-up
instructionsonpage 7-9. Bringthe engine andthe compressoruptothe operatingtemperature andthe
ratedspeedusingthe “ENGINERPM” knobon the control panel.2. To checkfor the properminimum
pressure valve (25) setting,turnthe “AIRPRESSURE GAUGE SELECTOR” valve (27) to the “SUMP”
positionand the “COMPRESSORPRESSURE LOAD SELECTOR” valve (9) to the “RUN” position.Whenthe
mainair valve (26) is opento the atmosphere,turnthe adjustingscrew inthe minimumpressurevalve
(25) clockwise toraise the pressure orcounterclockwise tolowerthe pressure.The propersetting
shouldbe 200 psig(13.8 bar).The pressure shouldbe readonthe “AIR PRESSURE” gauge (28) on the
control panel.3. To setthe LO-PR differential pilotvalve (6),showninFigure 7-16,setthe
“COMPRESSORPRESSURE LOAD SELECTOR” valve (9) onthe control panel tothe “START” (LO-PR)
positionandclose the mainairvalve (26)
172. Section7: CompressorOperation&Maintenance Manual T450WS 7-13 usingthe “AIR VALVE”
control.Loosenthe locknutonthe adjustingscrew of the LO-PR differential pilotvalve (6) locatedinthe
regulatormanifoldinsidethe control panel,asshowninFigure 7-17.Turn the screw clockwise toraise
the pressure orcounterclockwise tolowerthe pressure.The propersettingshouldbe approximately200
psig(13.8 bar) on the “AIR PRESSURE” gauge (28) whenthe compressorfullyunloads.Tightenthe

5. locknutonthe LO-PRdifferentialpilotvalve (6) forthe engine speedtoreach1800 rpm. Withthe engine
and compressorrunningatthe rated speed,slowlythrottlethe mainairvalve (26) until the pressure
selected(225) isshownon the “AIRPRESSURE” gauge (28). There shouldbe noair exhaustingfromthe
air muffler(37).If airis escapingfromthe air muffler(37),slowlyturnthe adjustingscrew
counterclockwise of the LO-PRdifferential pilotvalve(6) clockwiseuntil the airstopsexhausting.
Retightenthe locknutof the mainairvalve (26).Figure 7-16. PilotValve Figure 7-17.Differential Pilot
Valve Locations4.To setthe 350 differential pilotvalve (6),turnthe “COMPRESSORPRESSURE LOAD
SELECTOR” valve (10) to the “350” positionandclose
173. Section7: CompressorOperation&Maintenance Manual T450WS7-14 the mainair valve (27) using
the “AIR VALVE”control.Loosenthe locknutonthe adjustingscrew of the 350 differential pilotvalve (5)
on the regulatormanifoldinsidethe control panel,asshowninFigure 7-17.Turn the screw clockwise to
raise the pressure orcounterclockwisetolowerthe pressure.The propersettingshouldbe
approximately375 psig(25.9 bar) on the “AIR PRESSURE” gauge (28) whenthe compressorfullyunloads.
Tightenthe locknutonthe 350 differentialpilotvalve forthe engine speedtoreach1800 rpm
maximum.Withthe engine andcompressorrunningatthe rated speed,slowlythrottle the mainair
valve (26) until the pressure selectedHII-PR(350) isshownon the “AIRPRESSURE” gauge (28). There
shouldbe noair exhaustingfromthe airmuffler(37).If airis escapingfromthe airmuffler(37),slowly
turn the adjustingscrewcounterclockwiseof the HI-PR(350) differential pilotvalve (5) clockwise until
the air stopsexhausting.Retightenthe locknutof the mainairvalve (26).OtherCompressorSystem
AdjustmentsandInformationNOTE:Numberswithinbrackets( ) refertocalloutsfromthe System
Diagram (Figure 7-19) on page 7-15. • The pressure reducingvalve:auxiliaryair(33) isa valve that
providesreducedpressure airtooperate rigaccessories,handtools,etc.The valve mustbe adjustedto
give 100 psig(6.9 bar) on the “AIR PRESSURE” gauge (28) whenthe sumpair pressure isat maximum
operatingpressure.The “AIRPRESSURE”gauge is locatedonthe air-oil tanknexttothe regulator.•The
compressoroil flow:Dependinguponthe compressor’soperatingspeedandoperatingpressure,the oil
flowcan varybetween90 and110 gpm (340 and 416 lpm).The oil flow isalwaysmeasuredinthe main
oil line thatrunsfrom the compressoroil filter(29),showninFigure 7-18,at the outletof the
compressoroil cooler(30) to the oil stop valve (32),showninFigure 7-12. Figure 7-18. CompressorOil
FilterSullairTwo-StageCompressorSystemDiagramThe Sullair1050/350 psigtwo-stage compressor
systemdiagramisshowninFigure 7-19 onpage 7-15 and describedinTable 7-1on page 7-16.
174. Section7: CompressorOperation&Maintenance Manual T450WS 7-15 Figure 7-19. Compressor
SystemDiagram(Item1123-1120)
175. Section7: CompressorOperation&Maintenance Manual T450WS7-16 Table 7-1. 350 PSIGTwo-
Stage SullairCompressorSystem(Item1123-1120) DescriptionNo.DescriptionNo.Description1Sullair
2-Stage Compressor21 SeparatorDrain Line Orifice 2Coupling/Clutch22 SystemBlowdownValve 3
Engine 23 AirMuffler4 Control AirLine Filter24 SystemSafetyValve 5Differential PilotValve (HI-PR) 25
MinimumPressure/CheckValve 6DifferentialPilotValve (LO-PR) 26Main AirValve 7 AirBleedOrifice 27
AirPressure Gauge SelectorValve 8InletControl Cylinder28 AirPressure Gauge 9 CompressorLoad
SelectorValve 29CompressorOil Filter10InletButterflyValve30 CompressorOil Cooler11 AirCleaner
31 CompressorOil ThermostaticValve12Temperature Gauge & Switch32 Oil StopValve 13 Interstage
Pressure Gauge 33 Pressure ReducingValve (AuxiliaryAir) 14Discharge CheckValve 34 AuxiliaryAir
Pressure Gauge 15 Air-Oil Tank35 RunningBlowdownValve 16CompressorOil Fill 36Air Control Orifice

6. 17 CompressorOil Level Gauge 37 AirMuffler18 CompressorOil Drain38 AirBleedOrifice Plug19Oil
SeparatorElement39 ColdStart Valve 20 SeparatorDrain Line Strainer40 -
176. Section7: CompressorOperation&Maintenance Manual T450WS 7-17 CompressorSystem
Explanation(PerUse) The compressorsystemisdescribedbelow basedonwhenandhow the
compressorisused.Itdescribeshowthe compressorfunctionsduringstart- up,loadoperation(HI-PR),
loadoperation(LO-PR),andshutdown.Startup1. Ensure the inletbutterflyvalve (10) isclosedandthe
“COMPRESSORPRESSURE LOAD SELECTOR” valve (9) isinthe LO-PR(START) position.2.Uponstart-up,
the air pressure beginstobuildwithinthe compressorsystem.Thisallowsthe pressure differential
across the piston,showninFigure 7-20, to slowlyopenthe inletbutterflyvalve (10).Once the large end
of the inletcontrol cylinder(8) hasextended,itwill stayextendeduntilthe compressorisshutdownand
all the air pressure islostfromthe systemcausingthe large endof the cylindertocollapse toitsstart
position.The airbleedorifice (7) relievespressureonthe downstreamside of the differential valves
whenshutdownoccurs. Figure 7-20. InletButterflyValve Piston3.Withthe “COMPRESSOR PRESSURE
LOAD SELECTOR” valve (9) inthe LO-PRposition,the low pressuredifferential pilotvalve(6) controlsthe
small endof the inletcontrol cylinder(8).The small endof the inletcontrol cylinder(8),whichactuates
the inletbutterflyvalve (10) will fullystroke atapproximately75psig(5.2 bar).The LO-PR(low pressure)
differentialpilotvalve(6) will allowthe air-oil tank(15) pressure toincrease toapproximately200 psig
(13.8 bar) before itoutputsthe 75 psig(5.2 bar) signal necessarytofullystroke the inletcontrol cylinder
(8).Fullystrokingthe inletcontrol cylinder(8) unloadsthe compressorbyclosingthe inletbutterfly
valve (10).Because a substantial amountof airflowsthroughthe inletbutterflyvalve(10) whenclosed,
the signal fromthe LO-PR differential pilotvalve (6) willalsoopenthe runningblowdownvalve (35),
showninFigure 7-21. The air control orifice (36) issizedtobleedthisleakage tothe atmosphere
throughthe air muffler(37).ThisLO-PRselectiononthe “COMPRESSORPRESSURELOAD SELECTOR”
valve (9) isusedto
177. Section7: CompressorOperation&Maintenance Manual T450WS7-18 force the engine and
compressortowarm up at a reducedcompressorload.Figure 7-21.RunningBlowdownValve(left)
RunningBlowdownValve Breakdown(Right) 4.The systemblowdownvalve (22) closesaspressure
buildsatthe compressordischarge.5.The oil stopvalve (32), showninFigure 7-12, opensas pressure
buildsatthe compressordischarge.6.The minimumpressure/checkvalve (25),showninFigure 7-10on
page 7-6 opensat 200 psig(13.8 bar); therefore,the mainairvalve (26) needstobe closedtounloadthe
compressorat 225 psig(15.5 bar) at start-up.7. The engine (3) drivesthe compressor(1) througha
couplingorclutch (2) arrangement.Gearsinthe gearhousingof the compressorprovide the necessary
speedsthroughthe compressorstages.LoadOperation(HI-PR):1.Change the “COMPRESSORPRESSURE
LOAD SELECTOR” valve (9) to the HI-PRposition.Thiscausesthe inletcontrol aircylinder(8) tolose
pressure throughairbleedorifice (7) therebyopeningthe inletbutterflyvalve (10).The control of the
inletcontrol aircylinder(8) isnowdone bythe HI-PRdifferentialpilotvalve (5).The differentialpilot
valve (5) allowsthe air-oil tank(15) pressure toincrease to350 psigbefore outputtingthe 75 psig(5.2
bar) signal tothe inletcontrol aircylinder(8) necessarytounloadthe compressor.2.The control airline
filter(4) conditionsthe controlledairforuse inthe compressorcontrol circuit.3. The auxiliaryair
pressure reducingvalve (33) issetat 100 psig(6.9 bar) to provide reducedairpressure tooperate
accessoriesandhandtools.4. The main airvalve (26) isusedto modulate the amountof air discharged
intothe rig air network.5.Air deliveryismodulatedbythrottlingthe compressorinletbutterflyvalve

7. (10), whichisshownbythiscontrol circuit.6. The maximumengine speedis1800 rpm in the
COMPRESSORPRESSURE LOAD SELECTOR (9) control’sHI-PRposition.
178. Section7: CompressorOperation&Maintenance Manual T450WS 7-19 Load Operation(LO-PR):1.
Change the “COMPRESSORPRESSURE LOADSELECTOR” valve (9) tothe LO-PRposition.Thiscausesthe
inletcontrol aircylinder(8) toretract, therebyopeningthe openingthe inletbutterflyvalve (10).The
control of the inletcontrol aircylinder(8) isnow done bythe LO-PRdifferentialpilotvalve (6).The
differentialpilotvalve(6) allowsthe air-oil tank(15) pressure toincrease to225 psigbefore outputting
the 75 psig(5.2 bar) signal to the inletcontrol aircylinder(8) necessarytounloadthe compressor.2.The
control air line filter(4) conditionsthe controlledairforuse inthe compressorcontrol circuit.3. The
auxiliaryairpressure reducingvalve (33) issetat 100 psig (6.9 bar) to provide reducedairpressure to
operate accessoriesandhandtools.4.The mainair valve (26) is usedtomodulate the amountof air
dischargedintothe rigair network.5.Air deliveryismodulatedbythrottlingthe compressorinlet
butterflyvalve (10),whichisshownbythiscontrol circuit.6. The maximumengine speedis1800 rpm in
the COMPRESSOR PRESSURE LOADSELECTOR (9) control’sLO-PRposition.ShutDownDonot setthe
engine toidle whileinaloadcondition.Runninganidle engine whileinaloadconditionwill resultin
damage to the engine andvoidingthe warranty.1.Shut downissuggestedwhenthe compressor(1) is
unloadedandthe engine isatidle speed.The compressordischarge checkvalve (14) closestostop
suddenexpansionof airandoil out of the air-oil tank(15).The air cleanerisshowninFigure 7-22. Figure
7-22. AirCleaner2. Shutdownisaccomplishedbyshuttingoff the engine(3).
179. Section7: CompressorOperation&Maintenance Manual T450WS7-20 3. Shut downalsooccurs if
any of the followingsafetydevicesare activated:•Low engine oil pressure switch(notshownin Figure
7-19). • Highengine coolanttemperatureswitch(notshowninFigure 7-19).• Highcompressor
discharge temperature switch(12) issetat 255 °F (124 °C). 4. At shutdown,the lossof pressure atthe
compressordischarge causesthe systemblowdown valve (22) toopenand release the systempressure
throughthe air muffler(37).Italso causesthe oil stopvalve (32) to close and preventfurthercirculation
of the oil intothe compressor.5.The discharge checkvalve (14),preventsthe compressorfrom reverse
running.Reverse runningcouldbe causedbythe expansionof the airinthe air-oil tank(15) throughthe
compressorat shutdown.CompressorSystemDiagramExplanation(PerSystemandItems) The
compressorsystemdiagramisdescribedbelow based onthe oil systemandotheritemswithinthe
compressor.The itemsinclude gauges,safetyvalves,compressoroil fill,compressoroil drain,andthe
manifold.Oil System1.Oil flowsfromthe air-oil tank(15) due to the air pressure fromthe compressor
to the oil thermostaticvalve (31).If hot,the oil issentthroughthe compressoroil cooler(30).If cool,the
oil bypassesthe oil cooler(30).Oil thenflowsthroughthe compressoroil fluidfilter(29) andon to the
oil stopvalve (32) fordistribution tothe compressor(PortA).2.Oil fromthe oil separatorelement(19)
isreturnedto the firststage fromseparatordrain (scavenger) port(B) viathe separatordrain
(scavenger) linestrainer(20) and the separatordrain(scavenger) lineorifice (21).Gauges• The “AUX
AIRPRESSURE” gauge (34) isusedto determine whentoadjustthe auxiliaryairpressure reducingvalve
(33). • The “AIR PRESSURE” gauge (28) (inthe control panel) measuresthe air-oil tank(15) pressure or
rig air networkpressure.Thisis accomplishedbyswitchingthe “AIRPRESSUREGAUGE SELECTOR” valve
(27). Thisswitchingcanalsobe usedtocheck the pressure dropacross the oil separatorelement(19) to
see if itneedstobe replaced,asshowninFigure 7-26. Change the oil separatorelementif the pressure
drop is20 psig(1.4 bar) or higher.• The “INTERSTAGEPRESSURE” gauge (13) (inthe control panel)
measuresthe compressorinterstagepressure.Normal interstagepressureatthe sealevel withthe

8. compressorunderthe loadis60-65 psig(4.1-4.5 bar).• The “COMP TEMP” gauge (12) (inthe control
panel) indicatesthe compressordischarge temperature.
180. Section7: CompressorOperation&Maintenance Manual T450WS 7-21 • The compressoroil level
gauge (17), showninFigure 7-8 on page 7-5, visuallyindicatesthe oil level inthe air-oil tank(15) when
the compressorisnot inoperation.SafetyValveThe systemsafetyvalve (24),showninFigure 7-23,is
setto openat 400 psig(27.57 bar) and protectsthe air-oil tank(15) from over-pressurization.Figure 7-
23. SafetyValve Location(Left) andSafetyValve (Right) CompressorOil Fill If addingcompressoroil to
the air-oil tank,depressurize the system.Seriousinjuryordeathcan occur. The compressoroil fill (16),
showninFigure 7-24, is usedto addcompressoroil tothe air-oil tank(15).It ispart of the compressor
discharge line.Keepthe oil level inthe greenareaof the oil level gauge (17).The oil fill capisself
sealing.
181. Section7: CompressorOperation&Maintenance Manual T450WS7-22 Figure 7-24. CompressorOil
Fill CompressorOil DrainThe compressoroil drain(18),showninFigure 7-25, isusedto drainthe
compressoroil orcondensedwaterfromthe air-oil tank(15).Figure 7-25. CompressorOil Drain
CompressorMaintenance Continuedsatisfactoryperformanceof the compressorrequiresagood
maintenance schedule.The periodsbetweenmaintenance are foraverage conditions.Whenoperating
insevere environmental conditions,the periodsbetweenmaintenance mustbe shortened.Before
attemptinganymaintenance the air-oil systemmustbe depressurized.
182. Section7: CompressorOperation&Maintenance Manual T450WS 7-23 Oil System• Compressor
Oil Specification - The recommendedcompressorlubricantisaPAO-base syntheticaircompressor
lubricant.All compressorsare shippedfromthe factoryfullychargedwiththislubricant.The lubricant
provideslongoil sumpdrainintervalsandeliminatesoil relatedmaintenancecostsanddowntime.The
lubricantisavailable frommostoil suppliers.There isno“break-in”periodrequiredthatnecessitates
dumpingof the lubricantafterthe firstfew hoursof operation.•AddingOil - Lubricantis addedthrough
the fill plug(16) of the air-oil tank(15) thatis part of the compressordischarge line.Keepthe oil level in
the greenarea of the oil level gauge (17).The difference betweenthe extremesof the greenareais
approximately5U.S. gallons(19 l).Do notoverfill orunderfill the air-oil tank.Avoidbeingsplashedby
hot oil.Oil canreach veryhightemperatures,thuscausingseriousinjuryif itcomesincontact withskin.
• ChangingOil - Anoil drain(18) is providedatthe bottomof the air-oil tank(15) to drainthe oldoil
before addingnewoil.Whendrainingthe oil,remove the compressoroil fill plug(16) to balance
pressuresandallowfree flow.Drainthe oldoil whenitishotso that it flowsmore freely.Inaddition,
drainthe oil from the compressoroil filter(29),showninFigure 7-18,and replace the oldfilterelements
withnewfilterelements.Whenall of the oil hasbeendrainedfromthe air-oiltank(15),close all of the
openingsandfill itwithnewlubricantusingthe compressoroil fill (16).Runthe compressorfora couple
of minutesandshutdown.Recheckthe oil level onthe compressoroil level gauge (17).•Oil Change
Frequency - Undernormal operatingconditions,the lubricantshouldbe changedevery1000 hoursof
operation.Change the oil more frequentlyunderdirtyanddustyconditions.•Underno circumstances
shouldoil be addedwhenthe compressorisworkingandthe oil systemispressurized.Waituntil the
systemisdepressurized.Keepall oil incleancontainersand,if indoubt,filteritbefore addingoil tothe
compressorsystem.Donotuse any othertype of lubricantinthe compressorunlessyouhave consulted
withthe home office of Schramm;youmay voidyourwarrantyon the compressor.Excessive usage of
the compressorlubricantmaynot be the resultof the compressor.RefertoCompressor
Troubleshootingonpage 7-28 for troubleshootinginformation.•Oil SumpCapacity – See Section9 for

9. fluidandcapacityinformation.Once the unithasbeenrunandthe lubricantfillsthe oil filters,the oil
cooler,the oil lines,etc.,the air-oil tankoil level gauge (17) shouldbe locatedinthe greenarea.Check
the oil level whenthe unitislevel andNOToperating.The oil level mustbe maintainedforproper
compression.
183. Section7: CompressorOperation&Maintenance Manual T450WS7-24 Oil FilterOil filterelements
needtobe changedwhenthe pressure dropacrossthemreaches25 psig(1.7 bar).At that point,the
compressorfilterindicatorturnsredandindicatesthatthe elementsneedtobe serviced.Remove the
filterhousingandthrowawaythe usedfilterelementsfromthe compressoroil filter(29) assembly.
Cleanthe housing.Replace the rubberseals.Oil SeparatorThe compressoroil separatorislocatedinthe
vertical sectionof the air-oil tank(15).Itconsistsof a renewablecartridge-type orseparatorelement
(19). The separatorremovesthe oil fromthe air.Oil trappedby the separatorelementisreturnedtothe
compressorthroughthe separatordrain(scavenger) line(21).Oil impinging(striking) directlyuponthe
separatorelement(19) drainsintothe oil sump.SeparatorReplacementBefore attemptingany
maintenance the Air-Oil systemmustbe depressurized.Servicingthe compressorsystemwithout
depressurizationcancause seriousinjuryordeath.The oil separatorelementisillustratedinFigure 7-26
and describedinTable 7-2.Duringthe separatorreplacementinstructions,anynumbercalledout
between( ) referstothe numbershowninFigure 7-26 and describedinTable 7-2.Figure 7-26. Oil
Separator
184. Section7: CompressorOperation &Maintenance Manual T450WS 7-25 Table 7-2. Oil Separator
Description(see partsbookforpartnumbers) NumberItemDescription1Screw Capsand Washers
ScrewCaps NC3/4x3-1/2 SA-193 and WashersHT SAE ¾” for the air-oil tankcoverplate.2 CoverPlate
Air-Oil TankCoverplate.3ScavengerLine Oil thatpassesthroughthe separatoriscollectedbymeansof
a separatordrain (scavenger) line andreturnedtothe compressorinlet.4Oil SeparatorElementThe Oil
SeparatorElementthatisto be replaced.5 Seal Plate/SealSurface Sealsatthe base of the Oil Separator
that helpkeepthe separatorelementandfluidinthe casing.Toreplace the Oil SeparatorElement:1.
Usinga wrench,remove the screwcaps(1) on the air-oil tank’scoverplate (2).2.Remove the air-oil
tank’scoverplate (2) fromtop of tank tower.Save the hardware (1).Theywill be usedwhenresealing
the cover plate (3) ontothe air-oil tank.3.Remove andproperlydiscardthe oldOil SeparatorElement
(4).4. Cleanthe seal plate andsealingsurfaces(5).Sealsare partof the Oil SeparatorElement.Make
sure the sealsare alsoclean.5. Install the new Oil SeparatorElement(4).Installbottomof element
betweenthe tabsinthe bottomseal plate (5).6. Install the air-oil tank’scoverplate (2).Make sure
sealingsurface isclean.7.Install the remaininghardware (1).Torque the screwsto280-300 lb-ft.8.
Checkthe scavengercircuit(3) for obstructionwheneverthe separatorelementischanged.Oil Cooler
The air-cooledcompressoroil coolerisa radiatortype assemblyof finsandtubesmountedwitha
hydraulicallyoperatedsuckerfan.Tomaintainoptimumcoolingefficiency,itisimportanttokeepthe
outside of the tubesfree fromdirtbuildupandany accumulationof debris.ClutchAn adjustableclutch,
showninFigure 7-27, is usedto be able to disconnectthe compressorfromthe engineif necessary.To
obtainmaximumserviceabilityandproperlife fromthe clutch,itsadjustmentmustbe periodically
checked.Itisparticularlyimportanttore-adjustthe clutchshortlyafterithasbeenputinto service.The
initial break-inof the clutchplateswearsthe surfacessignificantly.Therefore,adjustthe clutchafter20
to 30 hoursof initial operation.Lateradjustmentsare baseduponwear andtear of the clutchplates.
The more oftenthe clutchisoperated,the more oftenitwill needadjustment.

10. 185. Section7: CompressorOperation&Maintenance Manual T450WS7-26 ClutchAdjustmentThe
clutchis illustratedinFigure 7-27.The clutchthrow-outyoke islubricatedwithgrease throughthe
grease fittingonthe side of the clutchhousing.Toadjustthe clutch:Figure 7-27. Adjustable ClutchDo
not attempttoadjustthe clutchat operatingtemperatures.The clutchmustbe relativelycool orat
ambienttemperature.Thiscanonlybe accomplishedafterthe machine hasbeenshutdownforseveral
hours.1. Disengage the clutchbyturningthe clutch handle beneaththe air-oil tankclockwise.2.
Remove the coverplate fromthe topof the clutch housing, asshowninFigure 7-28. Figure 7-28. Clutch
CoverPlate Removal 3.Turn the clutch sothat you have easyaccessto the detentpininthe clutch,as
showninFigure 7-29.
186. Section7: CompressorOperation&Maintenance Manual T450WS 7-27 Figure 7-29. ClutchDetent
Pin4. Depressthe detentpinwithascrew driver,asshowninFigure 7-6 on page 7-4 and turnthe
adjustingringclockwise (tothe right).5.Turnthe adjustingringclockwiseuntil ittakes260-270 lb-ft
(352-366 N m) on the operatingshaft throughthe clutchhousingtoengage the clutch.OR Turn the
adjustingringclockwise until youcannotengage the clutchanymore.Turnthe adjustingring
counterclockwise fromthispoint2to 4 adjustmentnotchesonthe adjustingring.Checkthe
engagementof the clutchbyfeel.The detentpinmustsnapinandout firmly.6.Clutchshaftmust be
lubricatedforproperthrow-outbearingmovement(every500 hours).CompressorandEngine Air
CleanersAirCleanerMaintenance informationcanbe locatedat AirCleanersonpage 10-38.
187. Section7: CompressorOperation&Maintenance Manual T450WS7-28 Compressor
TroubleshootingThissectioncoversthe mostlogical causesforcompressorfailuresandthe most
probable remedy.However,underthe manyconditionsof operationencountered,the maintenance
factor,age of unit,etc.,itisalmostimpossibletoforesee eachandeveryreasonforfailureanditscause
and remedy.If the reasonforfailure cannotbe determinedbythe providedinstructionscontact
Schramm forfurtherinformation.Compressorstartsbutshutsdownafter a shorttime • Highair
discharge temperature causedby:a) Low compressoroil levelb) Cloggedoil cooleroroil filterc) Stuck
thermostaticvalve d) Dirtonoil coolercore surfacese) An inoperativeoil stopvalve Compressordoes
not unload• The inletcontrol cylinderisnotoperatingoritssealsare leaking•The pressure regulators
needadjustment•Control the airlinesforrestrictionorbad leaks(e.g.control airline filterdraincock
leftopen) •The inletbutterflyvalveisstuckopen• The pilotvalvesneedadjustmentorthere isa
leakingdiaphragmLowDownHole Pressure •Faultyairgauge • Minimumpressure valve jammed•
Leaksin service line (drillstringconnectionsandcomponents) •Dirtyair cleanerelements•Inlet
throttle valve notopeningfully•Systemblowdownvalveleaking•Restrictedoil separatorelement•
Pilotvalvesimproperlyadjusted•Airexhaustingfromrunningblowdownvalve •Airdemandexceeds
compressorcapability•Main air valve notopenorpartiallyopenBlow downvalve continuestopassair
• Checkthe pilotline forbreaksorleaks• Ensure no dirtis inthe valve Excessive oil consumption•The
oil sumpisoverfilling•There are clogged,broken,orloose scavengerhose orlines
188. Section7: CompressorOperation&Maintenance Manual T450WS 7-29 • There isa clogged
scavengerdrainline strainerorfixedorifice,showninFigure 7-30• There isa rupturedoil separator
element•The oil isfoaming• The minimumpressurevalve couldbe inoperative•The scavengertube is
not bottomedinthe separatorelementFigure 7-30.ScavengerLine andFilterLow airpressure • Too
much airdemand• Main airvalve opentoatmosphere • Faultyminimumpressure valve•Excessive
leaksinservice airline •Dirty air cleaner•Inletbutterflyvalve notopeningfully,orstuckclosed•Blow
downvalve openorfaulty• Oil separatorclogged• Pilotvalvesnotadjustedproperly•Airexhausting

11. fromrunningblowdownvalve mufflerattoohighof pressure Highairpressure • Faultysafetyvalve in
air-oil tank• Faultypressure gauge • Oil separatorclogged•Inletbutterflyvalve notclosing
189. Section7: CompressorOperation& Maintenance Manual T450WS7-30 • Pilotvalvesnotadjusted
properlyInterstage pressure •Highinterstage pressure causedby:a) Restricteddischargelineb) A
discharge checkvalve thatisstuck closedc) A highpressure compressorstage malfunction•Low
interstage pressure causedby:a) Badgauge b) Aircleanerelementrestrictionc) Inletcontrol valve
won’topend) Signof malfunctionorimpendingfailure of low pressure stage Oil SeparatorExcessiveOil
Usage Oil carry-overthroughthe service airline maybe causedbya faultyoil separatorelement,faulty
minimumpressure valve,overfillingthe oil sump,oil thatfoamsexcessively,oraseparatordrain
(scavenger) linemalfunction.If oil carry-overoccurs,inspectthe minimumpressure valvefirstto
determine if itisopeningata verylowpressure (lessthan150 psig – 10.3 bar).If the minimumpressure
valve isnotthe problem,theninspectthe separatorelementtodetermineif the oil level inthe air-oil
tank isnot toohigh,the oil is notfoamingexcessively,the separatordrain(scavenger) lineisnotloose
or broken,the separatordrain(scavenger) line strainerisnotclogged,andthe separatordrain
(scavenger) lineorifice isnotplugged.Oil carry-overmalfunctionsof the oil separatorelementare
typicallydue to:• Using the oil separatorelementtoolong• Heavydirtor varnishdepositscausedby
inadequate airoroil filterservice •Use of improperoil •Using oil toolongfor the existingconditions
Rupturedor collapsedseparatorelementsare usuallydue toheavydirtor varnishbuildupinthe
filteringmedia.Anexcessive rigtiltangle couldhamperthe separatorandcause the oil tocarry-over.Oil
SeparatorExcessive Pressure DropThe oil separatorelementlife cannotbe predicted.Itdependsonthe
followingconditions:•Operation•Oil quality• Oil andair filtermaintenance The conditionof the oil
separatorelementcanbe determinedbythe pressure dropacrossit,or by visual inspection:•Pressure
Drop - the pressure dropacrossthe separatorelementisobtainedbyrunningthe compressoratits
ratedspeedandholdingthe 20 psig (1.4 bar) underthe maximumoperatingpressure onthe sump
pressure gauge bythrottlingthe mainairvalve usingthe AirValve control onthe control panel.Atthis
pressure setting,the inletcontrol cylindermust
190. Section7: CompressorOperation&Maintenance Manual T450WS 7-31 be holdingthe inlet
butterflyvalve open.If the inletbutterflyvalve isnotopen,adjustthe 500 psigdifferential plotvalve.At
thissetting,turnthe AirPressure gauge selectorvalve inthe control panel fromthe sumppositiontothe
line positionseveraltimes.Take note of the pressure difference.If the pressure difference exceeds20
psig(1.4 bar), the separatorelementshouldbe changed.•Visual Inspection - remove the separator
element,thenuse adroplightinside the elementtoreveal areasof heavydirt,varnishdeposits,or
rupturesinthe elementmedia.If the areascontainingthese containmentsare revealed,replace the
separatorelement.Frequentoil separatorclogging•Dirty oil • Defective orcloggedaircleanerelement
• Defectiveorcloggedoil filter•Leaks inintake airsystemCompressorRemoval If the compressormust
be removedforoverhaul or replacement:1.Remove the batterycables.2.Tag anddisconnectall hoses
and wiringtothe compressor.If the hosesare not tagged,itwill be difficulttorememberwhereeach
hose wasconnected.3. Remove the clampsfromcompressorairintake pipe andthe cap screwsfrom
belowthe inletbutterflyvalve.Remove the airintake piping.4.Disconnectthe air-oildischarge line at
compressor.There will be oil inthisline!The rigshouldsitforabout20 minutestoletthe oil cool.5.
Make sure the back of the engine issupportedonce the compressorisremoved.6.Install the liftingbail
or chainsaround the compressor.7.Remove cap screwsholdingcompressortoframe.Compressoris
nowreadyfor removal.Whenre-installingcompressor,reverse the above procedure.Lubricatethe

12. compressorrotatingpartsby pouring1 to 1-1/2 quarts (liters) of compressorlubricantintothe
compressorintake.
191. Section7: CompressorOperation&Maintenance Manual T450WS7-32 Do not exceed1to 1 ½
quarts (0.94 to 1.41 liters) of compressorlubricantintothe compressorintake.Checkthe compressoroil
level againbefore startingthe unit.Addif necessary.
192. T450WS 8-1 Section8: ShutdownandBreak-DownProceduresThissectionprovidesnormal and
emergencyshutdownproceduresandbreak-downinstructionsforthe T450WS Rotadrill.Schrammdrills
have beenengineeredwithconservativesafetyfactorsandincorporate othersafetyfeaturessuchas
machineryguardsandhydraulicsystemfail safe devices.A goodmaintenance programiskeyto
obtainingextendedcomponentlifeforyearsof reliableandsafe operation.Shutdowninstructionsare
explainedbelow.Break-downinstructionsare locatedonpage 8-4. Whenloweringthe mast,please
followthe detailedinstructionstoraise and lowerthe mastin RaisingandLoweringthe Mast onpage 3-
20. ShutdownInstructionsThe shutdownprocedure typesare normal andemergencyshutdown.The
normal shutdownprocedure shouldbe followedwhendrillingoperationiscomplete.The normal shut
downprocedure isdescribedinNormal ShutdownProcedure.If the rigmustbe abruptlyshutdown,
followthe emergencyshutdownprocedure.The emergencyshutdownprocedure isdescribedin
EmergencyShutdownProcedure onpage 8-3.Normal ShutdownProcedure 1.For rigs withonboard
compressors,followthe informationinSection7on page 7-11. It isrestatedas follows:a) Slowlyopen
the mainair valve toexhaustthe air fromthe air-oil tankto the atmosphere.Whenthe sumpair
pressure dropstobelow225 psig(15.5 bar),turn the “COMPRESSORPRESSURE LOADSELECTOR” valve
inthe control panel tothe “225” positionandclose the mainair valve byusingthe AirValve control.Set
the “COMPRESSOR LOAD/UNLOADSELECTOR” to the “UNLOAD” position.Donotturn the “COPRESSOR
LOAD LOAD/UNLOADSTART& STOPSELECTOR” from the “LOAD” to the “UNLOAD” positionwhenthere
ismore than225 psig(15.5 bar) sump airpressure inthe system.Damage can occur to the control
system.b) Slowlyreduce the engine speedto1400 rpm usingthe “ENGINERPM” knob.c) Once the
compressorunloads(the inletbutterflyvalvecloses),reducethe enginespeedto1200 RPM. d) Afterthe
compressortemperature dropsbelow180 °F (82.2 °C) Shut off the engine usingthe “NORMALSTOP”
controlson the control panel.
193. Section8: ShutdownandBreak-DownProceduresOperation&Maintenance Manual T450WS8-2 e)
The systemblowdownvalve shouldimmediatelyreleaseairfromair- oil tankreducingthe sumpair
pressure to0 psig(0 bar).2. Whendrillingwithmud follow mudsystemmanufacturerguidelinestoshut
downthe mud system.Drainthe mudand flushwithwaterif shuttingdownforanextendedperiodof
time.3. Turn the ignitionkeytoshutdownthe engine.4.Remove the key.5.Fastenall locksaroundthe
rig.Ensure nothingcan be alteredor damagedwhile the rigisshutdown.Onlyuse acceptable fluidsthat
meetthe ordinancesof yourlocality.Handle all fluidsappropriately.Neverspill ordrainfluidsintothe
environment.Disposeof fluidsaccordingtothe ordinancesof yourlocality.6.Drain the waterfromthe
waterinjectionpumpincoldweatherconditions.Addenvironmentallyfriendlyantifreezetothe water
injectioncircuit.Pumpsnotmaintainedthiswayincoldweatherconditionswill freezeand damage the
pump.7. Duringcold weatheroperation,flushenvironmentallyfriendlyantifreeze throughthe foam
injectionpump.Notflushingenvironmentallyfriendlyantifreezewillfreeze anddamage the foam
injectorpump.8. Drainthe waterfrom the air control compressorcoalescingfilter.Thisfilterislocated
inside the control panel onthe leftcontrol panel door.Methanol canbe addedto thisfilterinsevere
coldweathertopreventthe air controlsfromfreezingandsticking.Be sure the rigisnot runningandall

13. air has beenventedfromthe system.Unscrew the canisterfromthe filterhousingandaddabout2” of
methanol.Screwthe canisterbackonthe housing.Itmustbe hand tightened.Checkoftenandrefill as
necessary.Drainwaterfromcontrol air line filter.Thisshouldbe done aftershutdowntopermitwater
to completelyseparate fromthe oil.Inextremelycoldweather,drain1to 1 ½ hours aftershutdown
before the separatedwatercanfreeze.9.Drainwaterfrom the compressorair-oil tank. The crack ball
valve onthe bottomwill allowthe watertodrainand close.Reinstallthe plugintothe ball valve when
complete.
194. Section8: ShutdownandBreak-DownProceduresOperation&Maintenance Manual T450WS 8-3
EmergencyShutdownProcedure Thinkaboutsafetybeforeenteringintoanemergencyshutdown
situationthatiscausingor couldcause damage to the rig.Enteringintothisscenariocouldpossiblylead
to bodilyinjuryordeath.The operatorshouldmake everypossiblesafe attempttoshutdownthe rig,
but shouldneverplace himorherself inaperiloussituation.Anyimmediatethreatthatcouldcause
bodilyharmor deathshouldbe heededpriortopreservingthe rig.Situationsmayarise thatplace
people aroundthe drill riginimmanentdanger.Thesesituationsmightnotbe able tobe managedby
the drill rig.These scenariosincludefire,explosions,high-stresspressuresonthe rig,the rig liftingoff
the ground,etc. Inthese events,performthe emergencystopprocedure if there isnotime toperforma
normal stopprocedure.The emergencystopprocedure will cause the drill toquicklystop,whichcan
cause damage to the drill bit,drill pipe,andthe drill rig.The rigwill abruptlyshutdown.Abrupt
shutdowniscausedone of two ways:manuallybyanoperatoror automaticallyfroma control circuitin
the rig. The followingmanual emergencyshutdownprocedureistobe followedwhenanemergency
arisesandthe rigdoesnot automaticallyshutdown:1.Pushthe “EMERGENCY STOP” button,shown in
Figure 8-1. Thisbuttoncan be locatedonthe mainoperator’sstation,nearthe driver’scab.Other
emergencystopsmaybe locatedat otherareasof the rig.Locate all emergencystopsonthe rig priorto
operation.Figure 8-1.EmergencyStopButtons2. Exitthe rig, rigsite,etcaccording to normal
evacuationprocedures.Afterthe conditionsare safe enoughtoreturntothe rig, performany
maintenance thatisrequiredpriortostartingupthe engine.Make sure anyemergencystopbuttons
and engine emergencyshutdownmechanismshave beenreset.If anormal shutdownprocedure can be
performed,alwaysperformthe normal shutdownprocedure.Anemergencyshutdownprocedureisa
lastresort.
195. Section8: ShutdownandBreak-DownProceduresOperation&Maintenance Manual T450WS8-4
BreakdownProcedure Once drillingthe hole iscomplete,the rigmustbe shutdownand brokendown
for transport.1. Unloadthe drill pipe asexplainedinSection5.2. Shut downthe compressoras
explainedinSection7onpage 7-11. 3. Remove anyhosesorcontrolsto auxiliarymud,water,orair
equipment.4.Go to the operator’scontrol station.5. Turn the “ENGINE RPM” knobto the leftto
decrease the engine rpms.6.Shiftthe LazySusan towardthe mast by settingthe SUSAN SWINGcontrol,
showninFigure 8-2, to the “IN” position.Figure 8-2.SusanSwingControl 7.If necessary,secure the
winchline toensure itdoesnotinterfere withthe mastlowering.8.Lowerthe topheadto the Lazy
Susanloadpositiontosecure the pipe inthe Lazy Susanfor transportation.9.Remove all loose slips.10.
Secure the breakoutwrench.11. Remove mastlockpinsfromthe bottomof the mast. Mast lockpin
locationsare showninFigure 8-3. Figure 8-3. Mast Lock PinLocations
196. Section8: ShutdownandBreak-DownProceduresOperation&Maintenance Manual T450WS 8-5
12. For slidingangle masts,removethe angle braces,asshowninFigure 8-4.Figure 8-4. Angle Brace 13.
Lowerthe mast by settingthe MASTTILT control to the LOWER position,asshowninFigure 8-5.Figure

14. 8-5. Mast TiltControl 14. (SAMonly) Raise the mastslide usingthe “UP” positionof the “MASTSLIDE”
valve.Detailedinstructionstoraise andlowerthe mastare inRaisingandLoweringthe Mast on page 3-
20. 15. (SAMonly) Slide the masttothe upper-mostpositionusingthe “MASTSLIDE control.16. Lower
the mast usingthe MAST TILT controls.The rigmust be level.Itisrecommendedtohave a helperstand
at the frontof the rigin the line-of-sightof the operator.The helpershouldensure the properalignment
of the mastto the mastcradle.Lowerthe mastuntil itis nearthe mast cradle.Have the helperverify
that the mast will enterthe cradle
197. Section8: ShutdownandBreak-DownProceduresOperation&Maintenance Manual T450WS8-6
properlybetweenthe guides.Once verificationisapproved,completelylowerthe mastintothe cradle.
17. Lowerthe rig by raising(retracting) the rigoutriggers,asshowninFigure 8-6.Keepthe riglevel while
loweringthe rig.Thiswill preventthe rigfromtippingover.Figure 8-6.OutriggerRaised18.Fromthe
operator’sstation,use the “CONTROLPANELSWING”controls(if available)toswingthe control panel to
the transport position(intothe rig).19.Shutdownrig byturningthe keyto the OFFposition.20.A final
checkof the mast tiltcircuitshouldbe performed.