Causes of Piston Failure: Rust, Lubrication, and Contamination
Piston Rust:
Rust on the piston can lead to pitting, which, under repeated impact, can initiate cracks and ultimately result in piston failure.
Instructions on using water to suppress dust have been provided separately. In summary, double the oil consumption in the air line compared to dry operation. A few minutes before the end of the work, stop the water injection and dry the hammer with air. Then, pour two liters of oil into the hammer.
Piston Lubrication:
Insufficient or improper lubrication can cause excessive friction between the piston and cylinder, generating high temperatures and potentially altering the piston’s metallurgical properties.
Lubrication procedures have been provided in a separate document.
Contamination Ingress into the Hammer:
Contamination can enter the hammer through various pathways:
a. Drill pipe: Ensure the drill pipe cover is closed to prevent contaminants from entering the hammer. b. Hammer coupling: Ensure the hammer cover is closed. c. Water: Thoroughly filter the incoming water. d. Compressor air: Inspect the compressor filter regularly.
Contamination inside the hammer can cause scratches on the piston, which can become sources of cracks and fractures.
Furthermore, contaminants can lodge between the piston and the drill bit, causing deformation of the piston head. This deformation can lead to failure of the drill bit’s Teflon seal.
When the piston head is deformed, it should be repaired by machining. Since the piston in the H series hammer is double-sided, the repaired section should be placed towards the control tube. Replacing the Teflon seal alone will not solve the problem unless the Teflon diameter is machined to a smaller size.