MAINTENANCE, OPERATING AND SERVICE MANUAL
Contents
1. Casing 38mm Shoe length 3m Rod 1409mm hammer length 397mm The above diagram shows the length of starter casing required when using standard CDS RS equipment with the Bulroc HYPER 81 hammer If an alternative hammer is to be used the starter casing length can be calculated by either adding or subtracting the difference in effective length of the alternative hammer from that of the HYPER 81 hammer 114mm Reamed Dia 296mm Casing Shoe Size System parameters 4 CDS 240RS PARTS LIST 1 1a 1b 6 6a 6b COMPONENT PARTS Driver DHD380 CDS240DHO94RS Driver SD8 CDS240DH045RS Length less Foot Valve DHD380 Driver QL80 CDS240DH108RS 1b Length less Foot Valve SD8 Ring Bit CDS240RRING Length less Foot Valve QL80 Seloc Pin Set CDS240RSP Solid Retaining Pin CDS240RRP Segments 3 CDS240RSEG Foot Valve DHD380 94 Foot Valve SD8 BBF045 Foot Valve QL80 BBF108 Complete System CDS240094RS CDS240045RS CDS240108RS Total Weight DHD380 Shank Total Weight SD8 Shank Total Weight QL80 Shank 5 CDS 240RS SERVICING The CDS 240RS system is designed to reguire the minimum amount of service and maintenance However it is recommended that the system be stripped down every 250 metres and all the component parts checked for wear or damage Eventually the segments will need to be replaced and most likely2. CDS RS CDS 240RS MAINTENANCE OPERATING AND SERVICE MANUAL PATENTED AIRFLOW SYSTEM 1 INTRODUCTION The CDS 240RS Overburden System is a concentric drilling system designed to simultaneously case a hole through loose overburden conditions down into the solid bedrock with minimal disturbance to surrounding sub structures This system has a multi stage cutting head to guarantee the drilled hole is straight with minimum deviation The independent segments around the periphery of the head give equal concentric cutting forces resulting in fast low torque drilling Since down time is very costly this system is designed to require the minimum amount of maintenance However when parts do eventually wear the construction of the system is such that the areas of the cutting head which experience most wear can be replaced independent of the slower wearing areas and so minimise operating costs LIST OF CONTENTS GENERAL INTRODUCTION q USING THE CDS 2400RS 2 USING THE CDS 240RS SYSTEM ee 56 HOW THE SYSTEM WORKS REFURBISHING WORN EQUIPMENT RING BIT amp THE SEGMENTS 8 WELDING THE DRIVER 9 TROUBLE SHOOTING strana 10 12 2 USING THE CDS 240RS Drill Rigs Drill rigs on which the CDS 240RS is to be used should have a feed length at least one metre more than the longest casing This will allow sufficient clearance for any adapters or driv
3. position or if this doesn t happen then the segments will form three sockets in the rock that could generate extremely high torque loads once rotation was re applied 12 When the casing has been set to the required depth and when drilling in sticky ground care must be taken to clean out the inside of the casing before extracting the drillstring Water poured inside the casing repeatedly and flushed out will help the process On occasions it may be necessary to pull the CDS RS system back into the casing to flush out blockages To perform this task the system should be lifted into the hang position and rotated clockwise for 2 or 3 revolutions to ensure the bit face is clean The system should then be pulled back against the casing shoe and the air turned off At this point the rod should be marked to give a reference point for when the system is fed back through the shoe Reverse rotation for 1 revolution will then close the segments and allow the system to be pulled back into the casing Once inside the air can be turned back on and the system should then be moved up and down inside the casing until the blockage is cleared At no time must the system be rotated whilst it is inside the casing as this will cause the segments to jam against the casing wall 1 2 HINTS AND TIPS CONTINUED When the casing is clean the system should be fed back through the shoe using the reference point on the rod to indicate when it is through the shoe Once thr
4. the feed force or lift the CDS RS and the casing until rotation starts again Initially the casing may rotate but after drilling down the casing 1 2 meters it will stop rotating 8 Apply only light feed and reduced air pressure when setting the first casing and make sure the casing stays in line with the drill mast 9 When drilling through soft materials sand clays etc frequently lift the CDS RS and the casing a little to ensure that it is loose and to flush out any debris from the casing When the CDS RS is in the hang position all available air will go to directly flushing the casing In sand and gravels it is often preferable to reduce air and feed pressure to a minimum In all ground conditions it is good practice to lift the casing frequently to make sure it is loose and to clear all debris from the casing 11 HINTS AND TIPS CONTINUED 10 When drilling in sticky plastic clay the addition of water or even foaming agents in the hammer air may be necessary to maintain good flushing 11 When drilling through boulders or inclined rock faces the fact that this concentric system has a number of independently operating segments With a concentric system the independent segments only require a very small amount of movement to travel from the open to closed position this is somewhere in the region of 20 to 30 degrees rotation of the system Consequently if you attempt to hammer without rotation then the segments will swing back i
5. weld breaking through and to help alignment a 3mm wide land should be left on each end face If the casing is the threaded type then it must be left hand Because of the cost of the thicker walled casing required to produce a thread it is normal practice to have threaded joints welded on to the end of thinner casing thus keeping the cost to a minimum If this is the case then great care must be taken to ensure the joints are true and concentric to the casing An out of line joint can result in either the system jamming inside the casing or the casing jamming in the hole As with welded casing the joints should have bevelled end faces to prevent weld breaking through into the inside of the casing 3 Check the casing shoes before the job starts The inside diameter of the shoe should be within the following tolerances CDS 240RS 241 5 4 Check the length of the casing shoes When in position against the drive shoulder on the driver there should be between 12mm and 25mm clearance between the back face of the segments and the front face of the casing shoe depending on the size of the system This distance will increase as the drive shoulder and or the casing shoe wears 5 Make sure the segments swing from open to closed position freely by hand 6 Use the diagram on page 3 to make sure the correct length of starter casing has been calculated 7 When drilling commences use slow forward rotation If jamming occurs ease back on
6. 3 The weld must be applied in single runs around the shoulder area building it up to as near the original shape as possible Use 1mm CARBOFIL 1 AWSAS 28ER 805 9 or equivalent Bit Holder Bit Holder After Re machining 4 After welding the holder must be slow cooled This can be achieved by either burying the holder in a tank of vermiculite or similar or by wrapping it in an asbestos blanket This slow cooling is a very important part of the process Rapid cooling can cause cracking 5 Once the holder has returned to room temperature it should be turned on a lathe back to its original shape Dimensions for turning are given in the table on page 3 The correct shape is important to avoid rapid wear of the casing shoes and subseguent wear of the bit holder If a lathe is not available then a small hand grinder can be used to reform the drive shoulder Great care must be taken to get the surface even and correctly form the 30 degree shoulder if the surface is uneven and the angle incorrect it will lead to premature wear and jamming 10 HINTS AND TIPS Always Do the Following 1 Make sure the Driver will pass through all the lengths of casing intended for the job If the casing 15 to be welded extra clearance should be allowed for weld spots which may break through into the inside of the casing 2 If the casing is to be welded then the ends should be bevelled at an angle between 45 and 60 degrees To prevent
7. ch is welded into the starter casing Since the casing does not rotate with the drill tubes the torsional loads are relatively low and so either left hand threaded or welded casing can be used REFURBISHING WORN EQUIPMENT The Ring bit and Segments The most frequent cause of button failure can be attributed to over drilling and incorrect button regrinding Regrinding at regular intervals with the correct equipment not only improves component life but also improves production and reduced overall drilling costs 1 Buttons should be reground to their original shape when the wear flat is 1 3rd the diameter of the button 2 If the button is cracked or chipped it should be ground back flush to the steel matrix It is possible to carry on drilling with a number of broken buttons if they are ground back in this way providing they are not affecting the gauge diameter or are not adjacent to each other since this would affect the smooth rotation of the bit 3 After regrinding check the protrusion heights of the buttons If a button protrudes too far from the steel body it will cause premature failure of the button The side protection buttons should be ground back flush with the body The gauge buttons should be ground back until their protrusion height is 1 2 their diameter To perform the task of regrinding correctly we recommend the use of a hand held grinder with gravity fed water supply necessary to cool the impregnated diamond grind
8. e subs required by the system Drill Tubes We recommend standard 4 7 api reg x 5 7 OD 140mm OD drill tubes should be used with this size system However it will be necessary to effectively reduce the annulus area between the drill tube and the ID Inner Diameter of the casing which in turn will increase the up hole velocity of the exhaust air for efficient removal of the drill cuttings and also prevent blockages occurring inside the casing The drill tubes should therefore be sleeved using standard 8 casing 8 625 219mm The hammer must also be cased over the full length down to the chuck The length of the sleeved drill tubes should be identical to the length of the casings to maintain the initial protrusion length from the starter casing so as to ensure access to the spanner flats on the drill pipes UP HOLE VELOCITY FORMULA METRIC VM Y CFM x 1305096 DM VM Velocity in m min Y Volume of air passed by Hammer at the selected pressure m3 min DM Diameter of casing bore squared in mm Dm Diameter of tube sleeve squared in mm UP HOLE VELOCITY FORMULA IMPERIAL VF Y CFM x 183 4 D di VF Velocity in feet min Y Volume of air passed by Hammer at the selected pressure Ft min DI Diameter of casing bore squared in inches Di Diameter of tube sleeve squared in inches 3 CALCULATING LENGTHS FOR STARTER CASINGS 1508mm Starter Casing including shoe
9. ed drive ring onto the driver and rotate clockwise until it stops SELOC PIN SET RETAINING PIN Now insert a NEW retaining pin and gently drive home with the punch before finally inserting a new Seloc Pins Finally ensure a spot of tack weld is applied to secure the Pins in position so they cannot come out Recommendations for refurbishing worn components are given in page 8 HOW THE SYSTEM WORKS 9 The Bulroc CDS 240RS overburden system is designed to enable the operator to drill and simultaneously case a hole through loose overburden ground conditions down into solid rock See diagram 1 After reaching the required depth the segments can be moved into the closed position by pulling the system up against the casing shoe and counter rotating If the hole has reached solid rock at its required depth then the system can be closed by resting the system on the bottom of the hole and again counter rotating With the segments fully closed the system can now be retracted through the casing leaving a clean cased hole See diagram 2 Should it be necessary to drill on further into the solid rock the CDS RS system can be detached from the Hammer and replaced with a conventional drill bit that can pass through the casing shoe See diagram 3 The Bulroc CDS RS overburden system simultaneously cases the hole by means of a shoulder on the driver This shoulder locates against the top face of the casing shoe whi
10. ing cups A combo type grinding cup of the approximate diameter will remove the surrounding steel matrix and reform the carbide button at the same time The Driver The shoulder on the driver where it contacts against the casing shoe will eventually wear This is quite normal and to be expected However when the drive shoulder does become worn to a taper shape it will begin to jam in the casing shoe At this point it will be necessary to re form the drive shoulder back to its original 30 degree angle by welding up this area of the original shoulder It is important that the following procedures are strictly followed to avoid damage and cracking of the driver The same type of wear will also occur on the replaceable drive ring if you are using this design of driver However in this case all that is necessary is to burn off the old worn ring and replace it with a new drive ring This comes in two halves that require welding around the driver recess It is important that the system is used with a well fitting casing shoe which has the same 30 degree angle A badly worn casing shoe will cause rapid wear and unnecessary wear to a new or re formed drive shoulder on the driver 9 WELDING THE DRIVER WELDING PROCEDURES 1 The bit holder must be preheated to between 200 C and 250 C before any welding takes place 2 This temperature must be maintained throughout the welding process check temperature frequently using temp sticks
11. nto the closed position causing the system to produce a socket in the rock that is only the diameter of the pilot bit So once rotation is resumed the segments cannot open back out as they are retained by the sides of the rock socket To prevent this occurring a concentric system should have its RPM increased and feed rate reduced once it starts to encounter boulders or inclined rock By doing this you guarantee that the segments remain in the open position even if their contact with the rock is intermittent The system should then be fed slowly into the boulder or rock face until continuous cutting can be heard At no time must the rotation be stopped whilst hammering is taking place If at any point the system starts to jam against the inclined face it must be immediately pulled back and then slowly fed forward back into the rock Once the system has formed a complete socket in the rock the speed and feed can be reduced back to the correct rates suitable to the type of rock being drilled The segments on this concentric system should be much easier to move from open to closed position and consequently the most important consideration when using a concentric system is to maintain clockwise rotation throughout the entire drilling cycle The only time reverse rotation should be applied is when you wish to close the segments and at no time should the system be hammered without rotation as this will either allow the segments to vibrate back into a closed
12. ough the shoe the system can be rotated clockwise to open out the segments 13 Always re grind worn buttons Never do the Following 1 Penetrate too fast in loose ground Overfeeding will bury the CDS RS and block the casing with nowhere for the hammer air to exhaust hence stopping the hammer Always give the flushing air a chance to bail out the debris and keep the casing clear 2 Over rotate This will lead to premature button wear In rock or boulders rotation of the CDS 240RS should be between 14 to 16 rpm In loose ground conditions this can be increased by 50 3 Apply weld to either the ring bit or the segments This can lead to cracking and button failure No warranty can be considered on these parts if there is any evidence of welding Bulroc s CDS RS range of overburden drilling systems feature patented Bulroc Airflow technology This document is 2013 Bulroc UK Limited All rights reserved Unauthorised duplication or distribution prohibited by law PATENTED AIRFLOW SYSTEM ALWAYS THINK SAFETY FIRST gauia This manual is published by and copyright of Bulroc UK Ltd All Rights Reserved Always operate your Bulroc drilling equipment according to the instructions contained within this operating manual Further copies of this manual can be downloaded from the Bulroc website www bulroc com For urgent support or sales enquiries call Bulroc on 44 0 1246 544700 or Skype BULROCUKSALES E amp O E This
13. page Ieft intentionally blank Bulroc UK Limited Turnoaks Business Park Burley Close Chesterfield Derbyshire United Kingdom S40 2UB Tel 44 0 1246 544700 Fax 44 0 1246 544701 E mail info bulroc com Web www bulroc com 2012 Bulroc UK Limited All Rights Reserved
14. the buttons on the ring bit will reguire re grinding At this time the following procedures must be followed 1 First remove both the Retaining Pin 4 and Seloc Pins 3 holding the Ring Bit by grinding out the tack weld push out as shown Hammering gently will force the Pins out of their housing but should this prove difficult applying liberal amount of penetrating oil should ease the process 2 Once the Pins are removed rotate the Ring anti clockwise until it stops then pull forward to remove 3 The segments are now free to be withdrawn from their sockets 6 CDS 240RS SERVICING CONTINUED At this point the segment bushes or sleeves can be examined These bushes are pressed into the driver to prevent wear whilst the segments are cutting and they are manufactured from hard wear resistant steel that should outlast many segment changes before they will require replacing Before re assembling the system it is important to check the condition of the slots in the driver where the ring bit lugs locate These slots may show some degree of wear and deformation and any signs of deformation must be removed using a small pencil grinder or similar to ensure correct location and drive of the ring bit This is particularly important if a NEW ring bit is being fitted to a WORN driver Re assembly Instructions To re assemble the system insert the new or re sharpened segments into their sockets and slide the new or refurbish
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