Page 36 - Diamond Products Catalog

Water pressure is not an indication of water flow in positive displacement water pumps.
To calculate water flow, measure pump rpm with a tachometer. Pump output is proportional to output at max speed e.g. FMC LO918 Nameplate, Max Speed: 625 rpm Output Flow: 20.2 GPM Measured rpm of 240 rpm. Output flow is equal to 625 rpm/240rpm X 20.2 GPM = 7.5 GPM
Sharpening
Sharpening, also known as stripping, is the
act of conditioning the bit to regain or improve penetration rate. Sharpening of the bit occurs when sufficient weight is applied to create contact between the supporting matrix and
the rock. The friction on the matrix removes
it and exposes new diamonds. Sharpening is necessary when a new bit is started, if too low
a bit has been selected for the rock type or if an impregnated bit has been allowed to slow down and polish. Active sharpening should be done as little as necessary because it reduces bit life.
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© Copyright 2014 Boart Longyear. All rights reserved.
Bit performance and wear will vary due to, and may be adversely affected by, a variety of factors including (i) operator skill and experience, (ii) drilling equipment and techniques, (iii) bit handling, care and maintenance, (iv) varying geological formations and conditions, (v) subsurface structures and hazards, (vi) extreme environmental conditions, and (vii) use of bits outside of recommended operating parameters. Accordingly, except for the limited warranties expressly set forth in Boart Longyear’s standard sales terms, Boart Longyear does not warrant or guaranty bit performance or wear. Boart Longyear bits and other products are intended for use only by skilled drill operators and other personnel who have been provided adequate product training. Improper or unintended use of Boart Longyear bits and other products may result in property damage, bodily injury, or death.
Quick Tip:
• Add WOB until torque rises, once penetration rate increases, reduce WOB to maintain desired penetration rate.
• Reduce RPM by 1/2, wait until torque and penetration rate rises. Return speed to normal operation.
• If 1 and 2 are insufficient (up-holes, under- powered rigs, or too low a series bit), reduce RPM by 1/2 and reduce water flow. Wait until torque and penetration rate rises. Return speed and water flow to normal operation.
• UMXTM bits have a greater rise in torque on initial sharpening. WOB needs to be held until penetration rate increases. Reduce WOB to maintain desired penetration rate once sharp.
Quick Tip:
If frequent sharpening is required, a higher series bit formula should be selected. Under
no circumstances should any acid be used for sharpening a Boart LongyearTM impregnated bit. Also, shutting off the water flow while drilling and waiting for the bit to "bite", is not recommended by Boart Longyear as a method of sharpening due to the likelihood of burning in the bit.