IMPACT RING BIT SYSTEM Care & Maintenance Instructions

Transcription

1 IMPACT RING BIT SYSTEM Care & Maintenance Instructions 646 Thompson Road Thompson, CT USA Phone: +1 (860) Fax: +1 (860) Numa All Rights Reserved

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3 - TABLE OF CONTENTS - Section I - Description... 1 Features... 1 Section II - Preparation... 2 Section III - Operation... 3 Section IV - Maintenance... 5 Impact Ring Bit

4 LIMITED WARRANTY WARRANTIES AND REMEDIES Numa warrants that the Product will be new and free from defects in material and workmanship under normal use as contemplated by this Contract for a period of six (6) months from the date of shipment. Except for the foregoing warranty, Numa disclaims all warranties and representations wherever made, including warranties of merchantability, durability, length of service, or fitness for a particular purpose. Any alteration or modification of the original product without the express written consent of NUMA will void this warranty. REMEDY If, during such warranty period, Buyer promptly notifies Numa in writing of any defect and establishes that the above warranty is not met, Numa shall either repair or replace the Product or credit the customer, as it deems necessary to meet the warranty. Such repair, replacement, or credit of Product shall constitute complete fulfillment of Numa s obligation under this warranty, and upon the expiration of the original warranty period, all of Numa s obligations hereunder shall terminate. LIMITATION OF LIABILITY Numa shall not be liable to Buyer whether in contract, in tort (including negligence and strict liability), under any warranty or otherwise, for any special, indirect, incidental or consequential loss or damage whatsoever, including (without limitation) loss arising from delay, cost or capital and loss of profits or revenues. The remedies set forth in this Contract are exclusive, and the total cumulative liability of Numa under this Contract or for any act or omission in connection therewith or related thereto, whether in contract, in tort (including negligence and strict liability), under any warranty or otherwise, is limited to the price paid by Buyer for the Product. The WARNINGS, CAUTIONS and NOTES used throughout the text of this instruction book are defined as follows: WARNING CAUTION NOTE A specific procedure or practice that must be strictly followed, or a specific condition that must be met, to prevent possible bodily harm. A specific procedure or practice that must be strictly followed, or a specific condition that must be met, to prevent damage to the equipment. Important supplemental information. Numa,Champion, Patriot, and Impact Ring Bit System are registered trademarks of Numa. Impact Ring Bit

5 Description Section I - Description The Numa Impact Ring Bit System is designed for the efficient installation of casing in hard rock horizontal drilling applications. The ring bit system is used in conjunction with an air percussive down-hole-hammer. This allows for the casing to be installed while simultaneously drilling the rock bore. The system consists of a ring bit, center bit, and split drive shoe, and work in conjunction with the casing, hollow stem auger flights, and horizontal boring machine. The down-hole-hammer provides the power needed to fracture the rock formation, while the auger fitted to the backside of the hammer carries the fractured cuttings back through the casing for removal. The ring bit is inserted into the end of the casing along with the split drive shoe. The split drive shoe is welded to the casing, allowing the ring bit to freely turn independently from the casing. The center bit is connected to the hammer by bit retaining rings, and the male splines align with the female splines in the ring bit. Features Revolutionary two-piece ring bit system that simultaneously installs casing while drilling Drill holes 5-1/4 to 50-1/2 ( mm) in diameter Designed for use with horizontal or conventional DTH hammers. Systems available for steel, P.E. or concrete/clay pipes and casing Fastest penetration rates for setting casing in rock formations Drills with extreme accuracy - on-grade and on-line Ring and center bit may be reused on multiple jobs Center bit and hammer may be retracted while leaving the casing installed Large air flushing holes for better hole cleaning Thick ring bit promotes longer and deeper bores Center Bit Ring Bit Auger Casing DTH Hammer Split Drive Shoe 10/17/05 Impact Ring Bit Page 1

6 Preparation Section II - Preparation Welding of the split drive shoe to the casing and subsequent casing weld joints is one of the most critical procedures in the installation of casings. Poorly welded joints may separate and or fracture from impact vibration during the drilling process and may result in the loss of casing sections or tooling in the borehole. Weld beads should not protrude excessively beyond the outside diameter of the casing. This will cause unnecessary friction on the outside of the casing, make advancement difficult and exert high stresses on the weld joints. Excessive weld should be ground off. If this becomes necessary, grinding should be done in a linear fashion rather than around the circumference. Grinding marks around the circumference can generate stress risers and weaken the weld joint. Alignment of the casing is critical. If the casings are askew, unnecessary friction will be applied to the outside of the casings and may apply bending stresses on the casing weld joints. It is recommended that a pipeline clamp be used for alignment and tack welding each section of subsequent casings. Before connecting the hammer to the rotary drive, all hoses and pipe work should be flushed with compressed air from the compressor. As each drill pipe is added, it should be connected to the rotary drive and flushed in the same procedure. Entrapped dirt in air hoses from manufacturing and handling, mill scale in auger flights, weld spatter etc., must be flushed from the system. Failure to do so can contaminate the down-hole-hammer and initiate irreparable damage in a very short period of time. Page 2 Impact Ring Bit 10/17/05

7 To Begin Drilling Section III - Operation Install the ring bit with the split drive shoe around it, into the first section of casing. Weld the drive shoe to the casing. Welding rods should be equivalent to AWS E8018-C1 or E8018-C2. These are 80,000 PSI materials with 2-1/2% - 4% Nickel for impact strength. Install the hammer and center bit into the casing, aligning the male splines on the center bit with the female splines in the ring bit. The face of the center bit should be flush with the face of the ring bit when properly engage. Connect the hollow stem auger flight to the backhead of the hammer. Connect the auger flight to the gear driven rotational motor of the horizontal boring machine. Connect the air hose from the compressor to the horizontal boring machine. Make sure all hoses and auger flights are blown clean of debris prior to connecting to the down-hole-hammer. Failure to do so could damage the hammer and void any warranty. All air hoses must be rated for a minimum of 500 PSI, and safety whip checks should be used on all connections. Turn the supply air on, making sure lubrication can be seen exiting the bit face. Turn rotation on. Rotation speed will depend on the rock formation. The harder the formation, the slower the rotation. The softer the formation, the faster the rotation. A good rule of thumb is rotation should be half of the drilling speed. An example would be if drilling 20 feet per hour, the rotation should be 10 rpm, but the best way to tell is by the wear on the carbides. Advance the entire system against the rock formation. The down-hole-hammer should be operated at a working pressure of PSI, which will achieve proper drilling speed. While drilling, it is normal to get a build up of cuttings around the bit face. When this occurs, the hammer should not be advanced, which will allow the casing and ring bit to drill ahead of the hammer and into the exhaust position. When this occurs, a surge of air will clean the cuttings from the bit face. 10/17/05 Impact Ring Bit Page 3

8 Section III - Operation When drilling in clays or "sticky" formations, injection of water to loosen up the formation will be needed. Water can also be injected when drilling rock, which will aid in dust suppression. Water should always be on site, and an inlet for hookup should be present, next to the lubricator inlet. A continuous supply of a high quality rock drill oil is needed to properly lubricate the down-hole-hammer. Consult the Care and Maintenance Instructions for your hammer to determine which products are recommended, and the proper amounts. Page 4 Impact Ring Bit 10/17/05

9 Maintenance Section IV - Maintenance In order to ensure that maximum life of the Impact Ring Bit System is achieved, the ring bit and center bit need to be closely inspected after each borehole is drilled. The following steps should be taken: All rolled over steel on the splines and air exhaust holes should be removed with the use of a hand held grinder and polishing wheel. Excess steel can create stress risers or cracks. Both components should be inspected for cracks. Inspect the shank interface with the bit shoulder. Cavitation will form on this surface after a period of time, and removal of any / all sharp edges can be performed with a de-burring tool or grinding stone. If the split drive shoe is to be used again, all steel roll over or burrs should be removed with a polishing wheel. Inspect the weld for any cracks. All the carbides should be inspected and re-shaped / sharpened when the flats worn on them exceed 1/4". If some carbide are broken but the bit is otherwise in good condition, Numa provides a factory carbide replacement service. Removal of steel around the carbide may be necessary to avoid torque buildup while drilling. In certain ground formations, the rock is more abrasive to the carbide than it is to the steel. Grinding down the steel will ensure proper protrusion of the carbides. Inspect the blow tube for cracks, chips, or wear. Replace if necessary 10/17/05 Impact Ring Bit Page 5

10 NOTES Page 6 Impact Ring Bit 10/17/05