Abstract: The 16MnIII steel forging pipe at the inlet filter unit for a skid mounted equipmet was found to be cracked after transporting to the site. The reasons for the cracking of the forging pipe were analyzed by macroscopic morphology observation, metallographic inspection, energy spectrum analysis, chemical composition analysis, hardness test, fracture morphology observation and finite element analysis. The results show that the cracking mechanism of the forging pipe was cleavage brittle fracture. Through the finite element simulation and the actual stress condition of the pipe system, it was concluded that the excessive bending moment of the pipe system during transportation might be the main reason for cracking at the variable wall thickness of the forging pipe.