a bomba de lama do eixo
Advantages of DTH Hammer Drilling
Environmental Considerations
Завод лопастного насоса шлака

The reason:
Inlet valve is not open or has silted
Suction line resistance is too high or blocked
Suction height is too high
Inlet valve is not open or has silted
Suction line resistance is too high or blocked
Suction height is too high