What is the minimum working water pressure at the drill machine?

What is the minimum working water pressure at the drill machine?

• A. 1 kg/cm2
• B. 0.5 kg/cm2
• C. 2 kg/cm2
• D. 1.5 kg/cm2

Answer: (A)

Water pressure at the drill machine must be enough to cool the bit and flush cuttings out of the borehole. A minimum of 1 kg/cm2 ensures the water jet reaches the drill face and provides a steady flow that suppresses dust and prevents overheating. If the pressure is only 0.5 kg/cm2, the flow is not adequate for effective cooling and flushing, leading to faster bit wear and more dust. Higher pressures like 1.5 or 2 kg/cm2 are not incorrect for these purposes, but they exceed the minimum required; the baseline safe minimum is 1 kg/cm2.

Water pressure at the drill machine must be enough to cool the bit and flush cuttings out of the borehole. A minimum of 1 kg/cm2 ensures the water jet reaches the drill face and provides a steady flow that suppresses dust and prevents overheating. If the pressure is only 0.5 kg/cm2, the flow is not adequate for effective cooling and flushing, leading to faster bit wear and more dust. Higher pressures like 1.5 or 2 kg/cm2 are not incorrect for these purposes, but they exceed the minimum required; the baseline safe minimum is 1 kg/cm2.