6 Inch DTH Water Well Drilling Tools Tungsten Carbide / Steel Material
Description
DTH hammer is used for drilling holes through a wide range of rock types, the variety of which continues to extend well beyond the original conception of early blast hole drilling.
Down-the-Hole refers to where the hammer action occurs when compared to drifter hammers, which hammer on top of the drill string. The DTH hammer piston always makes direct contact with the drill bit and there is generally no loss of transmitted energy as the hammer drills deeper, as is the case with drifter (top hammer) rigs.
We offers a wide range of DTH hammers suitable for a variety of drilling operations. Our Down the Hole hammers provide the most versatile and cost effective rock drilling method.
Application
The optimum range of hole size for blast hole drilling with DTH is 90 mm to 254 mm (3 ½”–10″). Smaller blast holes are generally drilled using tophammer, and larger holes generally use rotary machines.
In other applications, like foundation drilling, DTH hammers can be used with single bit in hole sizes up to . 750 mm (30″). With multiple hammer units CD (Cluster drills) drill holes up to 70″ or 1778 mm.
As a rule of thumb, the smallest hole diameter a DTH hammer can drill is its nominal size. A 4 inch hammer will drill a 4 inch (102 mm) hole. The limiting factor is the outside diameter of the hammer, because, as hole diameter reduces, airflow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 1 inch, so for a 4 inch hammer the maximum hole size is 5 inch (127–130 mm).
Choosing the right hammer is largely determined by hole size and type of rock formation. Ideally, the size of the hammer should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacuate the hole.
Advantages:
1. Out of the trouble of foot valve fracture and expansion and contraction.
2. Lower energy consumption and higher impact frequency. The drilling speed is 15%-30% higher than the one with foot valve.
3. Simple structure, reliable parts, long life span, easy and cheap maintenance.
4. Lower air and oil consumption. The oil consumption is about 10% lower than the one with foot valve.
DTH hammers specifications:
Hammers | Bit Shank | Connection | Matched Bit Dia |
1-3" Middle-low pressure DTH hammers | BR1 BR2 BR3 | RD40 box RD50 box API 2 3/8" Reg | 64-76mm 70-90mm 90-110mm |
3" hammers | DHD3.5 COP32/COP34 M30 | API 2 3/8"Reg | 90-110mm |
4" hammers | DHD340 COP44 QL40 SD4 M40 | API 2 3/8"Reg | 105-130mm |
5" hammers | DHD350 COP54 QL50 SD5 M50 | API 2 3/8"Reg API 3 1/2"Reg | 130-156mm |
6" hammers | DHD360 COP64 QL60 SD6 M60 | API 3 1/2"Reg | 152-203mm |
8" hammers | DHD380 COP84 QL80 SD8 M80 | API 4 1/2"Reg | 200-279mm |
10" hammers | SD10 NUMA100 | API 6 5/8"Reg | 254-330mm |
12" hammers | DHD1120 SD12 NUMA120 NUMA125 | API 6 5/8"Reg | 305-381mm |
Technical description.
The DTH dill comprise a narrow elongated tube which contains an impact piston, internal cylinder, air
distributor, check valve. The real, threaded top sub is fitted with a spanner slot and coupling thread for
connection to the drill tubes. The forward part, the driver check, also fitted with thread, enclose the
splines-equipped bit shank and thansfers feed force as well as rotation to the drill bit. A stop ring limits
axial movements of the drill bit. The purpose of the check valve is to prevent impurities from penetrating
the rock drill when pressedair is shut off. During drilling, the drill bit is with drawn inside the DTH and
pressed against the drive chuck. The piston strikes directly against impact surface of the shank of the bit.
Packing&Delivery
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