- © 2023 Numa Hammers. All Rights Reserved.
Technical Support
As the technological leader in the design of down hole hammers & bits, we feel its important to inform drillers of the most reliable ways to conduct down hole drilling. We provide various technical resources to assist drillers with properly maintaining their hammers & bits.
Hammer Component Solution Charts
Drilling through rock is a destructive process and from time to time drillers may encounter problems with their hammers. That is why we have formulated a “Solutions” chart for some of the more common technical support items involving down hole hammers. We are always happy to assist you with your technical questions. Please Contact Us with any questions that you may have.
If your hammer is not operating as expected, there are a few items you can easily check:
- Evaluate Compressor Output
- Properly adjust for temperature & altitude
- Conduct orifice test
- Check intake air filters
- Inspect Drill String
- Check for leaks throughout
- Evaluate pressure loss in hoses
- Calculate Proper Weight on Bit
- Adjust weight on bit
- Evaluate type of formation
- Inspect Blow Tube
- Measure for correct diamater and height
- Inspect for cracks and chips
- Investigate Hammer Choke
- Be sure the choke is seated properly
- Evaluate for proper choke selection
Backhead
| Problem | Cause | Solution |
| Thread Galling | Insufficient lubrication | Use proper amount and type of thread lubricant |
| Thread Breakage | Improper or damaged mating connection | Inspect mating connection with API gauges |
| Corrosion | Maintain proper lubrication | |
| Operating with damaged threads | See operator manual for repair instructions | |
| OD Body Wear | Abrasive formation | Increase hole cleaning |
Check Valve
| Problem | Cause | Solution |
| Not Sealing | Worn or cut seal surface | Replace check valve |
| Memory loss in spring/broken spring | Replace check valve spring | |
| Melting | Excessive temperatures | Inject water when stuck in hole |
| Check compressor discharge temperature | ||
| Replace check valve |
Feed Tube
| Problem | Cause | Solution |
| Galling on OD | Foreign material contamination | Cover drill string when making connections |
| Filter injection water | ||
| Inspect compressor air filters | ||
| Clean drill strings | ||
| Misalignment | Inspect feed tube seat in housing | |
| Inspect housing seat in case | ||
| Inspect compression spring for misalignment or breakage | ||
| Insufficient lubrication | Maintain proper lubrication | |
| Severely worn piston OD or case ID | Replace worn parts | |
| Cracked or Broken | Heat check damage | Maintain proper lubrication |
| Keep out foreign material | ||
| Maintain proper alignment | ||
| Corrosion | Maintain proper lubrication |
Piston
| Problem | Cause | Solution |
| Galling on Bearing Surfaces | Foreign material contamination | Cover drill string when making connections |
| Filter injection water | ||
| Inspect compressor filters | ||
| Clean drill string | ||
| Crack/Break on Bearing Surface | Heat check damage | Maintain proper lubrication |
| Keep out foreign material | ||
| Corrosion | Maintain proper lubrication | |
| Operating above recommended pressure | Change choke |
Case
| Problem | Cause | Solution |
| Rapid Wear on OD | Bits too small | Use larger diameter bit |
| Replace bits more often | ||
| Abrasive formation | Increase hole cleaning | |
| Cracks on Chuck End | Case worn below acceptable limit | Change bits more often |
| Replace case | ||
| Cracks in Thread Area | Corrosion | Maintain proper thread lubrication |
| Disassemble and clean for storage | ||
| OD impact from blunt instrument for disassembly | Use proper breakout tools | |
| Heat distortion from disassembly | Use proper breakout tools | |
| Weld on OD | Use proper breakout tools | |
| Improper breakout tools | Do not use pipe wrench | |
| ID Wear | Insufficient lubrication | Maintain proper lubrication |
| Foreign material contamination | Filter injection water | |
| Inspect compressor filters | ||
| Cover drill string during connections | ||
| Clean drill string |
Bit Retainer Rings
| Problem | Cause | Solution |
| Broken | Chuck collar worn below acceptable lengths | Replace rings |
Chuck
| Problem | Cause | Solution |
| Rapid Wear on OD | Bits too small | Use larger diameter bit |
| Replace bits more often | ||
| Symmetrical Wear Pattern on OD | Worn exhaust grooves on bit | Replace bit |
| Cracked Threads | Impact from blunt instrument for disassembly | Use proper breakout tools |
| Crushed case threads | Use proper breakout tools | |
| Corrosion | Maintain proper lubrication | |
| Worn Drive Splines | Excessive linear bit movement | Maintain proper lubrication |
| ID Galling on Bottom Seal | Foreign material contamination due to insufficient weight on bit | Increase Weight on Bit |
| Cracked/Mushroomed Collar | Insufficient weight on bit | Increase Weight on Bit |