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| Specification |
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DTH HAMMER |
Standard
Backhead Size |
Outside Diameter (mm/inch) |
Length
(mm/inch) |
1 |
4" HAMMER |
API 2 3/8 Reg. PIN, BOX |
98mm |
1096mm |
2 |
5" HAMMER |
API 3 1/2 Reg. PIN, BOX |
116mm |
1161mm |
3 |
6" HAMMER |
API 3 1/2 Reg. PIN, BOX |
138mm |
1386mm |
4 |
8" HAMMER |
API 4 1/2 Reg. PIN, BOX |
180mm |
1463mm |
5 |
10" HAMMER |
API 4 1/2 Reg. PIN, BOX |
225mm |
1450mm |
6 |
12" HAMMER |
API 6 5/8 Reg. PIN, BOX |
272mm |
1789mm |
7 |
15" HAMMER |
API 8 5/8 Reg. PIN, BOX |
350mm |
1777mm |
8 |
18" HAMMER |
API 8 5/8 Reg. PIN, BOX |
410mm |
1972mm |
9 |
24" HAMMER |
API 8 5/8 Reg. PIN, BOX |
520mm |
2027mm |
10 |
33" HAMMER |
API 8 5/8 Reg. PIN, BOX |
710mm |
2273mm |
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Outside Diameter
of Piston (mm/inch) |
Strock
(mm/inch) |
Weight
(kg/lbs) |
Shank Type |
1 |
75mm |
100mm |
44kg |
IR340, SD4 |
2 |
92mm |
100mm |
62kg |
IR350, SD5 |
3 |
108mm |
100mm |
108kg |
IR360, SD6 |
4 |
148mm |
100mm |
205kg |
IR380, SD8 |
5 |
174mm |
100mm |
350kg |
IR310, SD10 |
6 |
216mm |
100mm |
650kg |
IR112, SD12, N120 |
7 |
260mm |
100mm |
1080kg |
N120, N120S, N125 |
8 |
310mm |
127mm |
1492kg |
SD18, N180 |
9 |
381mm |
127mm |
2545kg |
SD24, N240 |
10 |
508mm |
127mm |
5800kg |
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DTH HAMMER |
100 PSI (7kg/cm2) |
150 PSI (10.5kg/cm2) |
200 PSI (14kg/cm2) |
1 |
4" HAMMER |
160 CFM |
230 CFM |
300 CFM |
2 |
5" HAMMER |
170 CFM |
285 CFM |
400 CFM |
3 |
6" HAMMER |
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385 CFM |
525 CFM |
4 |
8" HAMMER |
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610 CFM |
860 CFM |
5 |
10" HAMMER |
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690 CFM |
980 CFM |
6 |
12" HAMMER |
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880 CFM |
1250 CFM |
7 |
15" HAMMER |
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1650 CFM |
2090 CFM |
8 |
18" HAMMER |
1430 CFM |
2120 CFM |
3000 CFM |
9 |
24" HAMMER |
1760 CFM |
2540 CFM |
3580 CFM |
10 |
33" HAMMER |
3100 CFM |
4500 CFM |
6300 CFM |
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250 PSI (17.5kg/cm2) |
300 PSI (21kg/cm2) |
350 PSI (25kg/cm2) |
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1 |
380 CFM |
470 CFM |
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2 |
520 CFM |
645 CFM |
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3 |
675 CFM |
830 CFM |
951 CFM |
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4 |
1070 CFM |
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5 |
1290 CFM |
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6 |
1700 CFM |
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7 |
2680 CFM |
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| Correct rotation speed has a direct effect on both bit life and hammer performance. Proper rotation is essential for long hammer and bit life. Some common elements involving rotation speed are:
กแ Bit Life
Rotation Too Slow - The main purpose of rotating a down hole hammer and bit is to index the carbide button inserts to fresh rock on every impact. If the rotation is too slow the buttons may tend to bury themselves and this will result in an erratic rotation. Slow rotation can also result in the recrushing of the rock, also known as regrinding, which results in a rapid carbide wear.
Rotation Too Fast - Increasing the rotation speed will not necessarily increase the penetration rate. It will usually result in rapid gage carbide wear due to the high scraping forces rather than a crushing force.
กแ Hammer Performance
Rotation when drilling with a down hole hammer serves only two simple purposes.
1.Turning in a clockwise direction keeps the tool joints tight.
2.Rotation indexes the carbide buttons to fracture fresh rock with each impact.
An operator must learn to have a feel for finding the proper rotation speed that will deliver optimum penetration rate without sacrificing bit life. As a starting point an operator can use the following: |
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= 1/2 Penetration rate per hour in Feet. |
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= 1.6 X Penetration rate per hour in Meters. |
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| As an example, if the average penetration rate is 60 feet (18.3 m) per hour the revolutions per minute should be around 30. |
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