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DTH Hammer And Drill Bit Maintenance
Oct 19, 2018

DTH Hammer And Drill Bit Maintenance


 1, Before Use Inspection

If it is a new downhole hammer or a submerged hole hammer that has been serviced after use, it is necessary to carefully check the front and rear joints of the downhole hammer and the outer casing to be reliable before use. The piston moves freely, and the drill bit and the downhole hammers are used. The correct connection and associated drill pipe, drilling rig, air compressor are ready, and the connecting parts are reliable before drilling. If it has been used, the unmaintained DTH Hammer must be serviced before use.

  2. Lubrication 

The main purpose of lubrication is to reduce wear, rust, oxidation and gap seals. The down-the-hole hammer is driven by compressed air to drive the piston high-frequency motion to provide the rock bit with impact energy. Any high-speed moving parts need good lubrication, as well as the down-the-hole hammer. Each downhole hammer requires lubrication before and during use. 

If there is no lubrication or poor lubrication, it will cause early wear and fatigue to the internal moving parts of the down-the-hole impactor, especially the piston. Early fatigue cracks will form on the surface of the piston, which will seriously affect the life of the piston, and the cost of use will bring to our construction. inconvenient. Poor lubrication (left) and no lubrication (right) Early fatigue cracks on the piston Reasonable lubrication not only improves drilling efficiency, but also extends the service life of the downhole impactor. High-quality rock drilling lubricants have good resistance to wear, rust, oxidation, and foam. Most oil companies produce rock drilling lubricants. Therefore, we have to choose high quality rock drilling lubricants. For the use of lubricating oil, it is usually recommended to use 2 M3/Min for dry drill, and 0.114 liter of rock drilling oil per hour, for example: an air compressor that can provide 25.4 M3/Min gas volume, if all these gas quantities are supplied DTH impactor, then 25.4 M3/Min÷2M3/MinX0.114 liters = 1.45 liters of rock drilling oil will be required per hour. For wet drilling [water injection volume greater than 7L/min], lubrication is usually recommended. The rate of oil injection is 2 m3/min per gas, and 0.23 liters of lubricating oil is injected per hour. Leakage and oil loss caused by water requires additional lubricant to compensate. When there is foam around the borehole, more lubricant injection is required.

3. Maintenance After Use

Proper and timely maintenance also extends the life of the downhole impactor components and can significantly reduce the cost of ownership. Timely cleaning of the components of the downhole impactor, in many cases, the outer casing wears or the performance of the impactor is reduced due to wear of internal parts. At this time, the downhole impactor needs to be repaired and requires more detailed inspection. If the parts are in good condition, then it is necessary to apply the lubricating oil according to the assembly diagram and then store it properly. However, in order to ensure the best performance of your downhole impactor, the downhole impactor must be maintained regularly.

4, Regular Maintenance

Any equipment needs regular maintenance. Only we can do it carefully every time, you can use it when you need it. The down-the-hole impactor is also the same, but the maintenance of the downhole impactor after our maintenance is much simpler. It is only necessary to determine whether the internal piston is moving well and whether the lubrication is suitable. If you have used a DTH Hammer for a longer period of time then you need to routinely maintain the DTH Hammer: 

1) Replace all O-rings, check valve seals and springs inside the DTH Hammer. This ensures that the downhole impactor reduces air consumption. 

2) Ensure good lubrication of the moving parts (pistons) inside the DTH Hammer, remove all sharp corners and burrs formed during the use of the piston (recommended to remove the sharp corners of the piston and burrs with oilstone). 

3) Ensure that the check valve is unblocked and the return position is correct. 

4), the outer casing and cylinder wear condition, replace it as needed. 

5) Install correctly according to the installation order of the manual or the installation diagram. 

6), keep it properly.

  5, The Inspection of the Drill Bit

  The drill bit is a tool for crushing rock. Therefore, it is also the earliest part of the drill that has reached the end of its life. After each drilling, we must carefully check the wear of the drill bit.

  1), see how the alloy wear of the drill bit, when reaching or close to the alloy column 2/3, if it continues to be used, it will seriously affect the drilling efficiency, it should be sharpened, generally a drill bit is sharpened three times to reach the service life.

  2), see if the bit body is seriously worn, such as the cylindrical part of the alloy column leaking out of the drill body 3MM, it can not be followed

Continued use, need to be sharpened in time.

  3), the end of the drill bit, that is, the end face of the downhole impactor piston, the depth of the strike is more than 1mm,

A new drill bit needs to be replaced, as continued use can seriously affect drilling efficiency.

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