1. Broken drive sub
Causas probables:
– Gap between drive sub shoulder and out tube
– The joint is loose
- Presión de alimentación insuficiente
– Threads lacking lubrication
Acciones sugeridas:
– Implement appropriate tightening torque
– Enhance feed force in soft and unconsolidated rock conditions
– Ensure sufficient feed pressure
– Replace drive sub
– Use appropriate type and amount of grease to the drive sub threads
2. Cracked drive sub
Causas probables:
– Mishandling with a sledgehammer
Acciones sugeridas:
– Utilize tongs or chains to detach the drive sub from the out tube
3. Broken piston
Causas probables:
– Galling
– Corrosion at piston undercut
Acciones sugeridas:
– Clean the hammer with foam after drilling
– Check lubrication regularly; use the correct type and quantity of hammer oil
4. Piston cracked
Causas probables:
– Incorrect wrenching location
- Lubricación inadecuada
– Stuck in the hole
- Desviación del agujero
Acciones sugeridas:
– Inspect the lubrication system and ensure oil film is formed in the bit flushing holes
– Use wrenching areas to prevent distortion on the out tube
– Use water when stuck because friction can cause distortion
5. Cracked-out tube
Causas probables:
– Gripping in the wrong location with a jaw wrench
– Worn-out tube
– Corrosion
Acciones sugeridas:
– Apply correct tongue placements
– Replace the tube upon reaching the discard limit on the outside diameter
– Apply a corrosion protector for storage
6. Broken Top Sub
Causas probables:
– Improper torque between joints
Acciones sugeridas:
– Use minimum recommended torque
