Pneumatic DTH drilling rigs tend to have various malfunctions during daily drilling, which directly reduce construction efficiency. We sort out frequent on-site issues, analyze fault causes one by one and offer quick troubleshooting methods.1.Slow penetration rate and low drilling efficiency of the drill rig.

• Fault Phenomenon: Normal air supply, but slow drilling penetration and laborious rock drilling.
• Causes: Severe bit wear, worn valve plates inside the DTH hammer leading to insufficient impact force; air leakage at drill pipe joints causing air pressure loss; mismatched air pressure & air volume for rock hardness.
• Solutions: Regularly inspect and replace alloy drill bits; maintain DTH hammers timely by replacing seals and valve plates; coat thread grease on drill pipe threads to stop air leakage; match air compressor pressure according to rock hardness to guarantee rated working air pressure.

2.The DTH hammer fails to strike; the drill only idles without rock-breaking force

• Fault Phenomenon: The drill rotates normally, yet the DTH hammer fails to impact and cannot break rock.
• Causes: Hammer rusting due to water ingress and stuck internal piston; air channels blocked by pipeline impurities; air pressure below the starting requirement of the hammer.

50. Solutions: Install water separators for rainy construction to prevent water from entering the hammer; clear pipeline impurities and blow air hoses before startup; adopt matched air compressors to meet minimum starting pressure; fill lubricating oil to maintain internal hammer parts before long-term shutdown.

3.Drill pipe threads frequently seize up and are difficult to disassemble

• Fault Phenomenon: Drill pipe threads get stuck tightly after drilling, hard to disassemble and delay construction progress.
• Causes: No special thread grease applied on joints; mud and grit embedded into threads during drilling; thread deformation and abrasion caused by violent twisting during assembly & disassembly.
• Solutions: Evenly coat dedicated thread grease on joints before connecting drill pipes; wash sediment off threads immediately after drilling; use special pipe breakout tools instead of brute force knocking; clean and anti-rust threads before storage.