Safety Assessment to Tower Cracked by Over-pressured Hydrostatic Test

An xylene tower of a petrochemical plant was cracked on the wall by over-pressured hydrostatic test after its construction.The over-pressure also damaged the inner supporting and outer stiffening rings,caused plastic deformation to the cylinders.By overall inspection and safety assessment,the tower was considered to be conformity with the requirement to use.The economic lost was avoided from not rejecting the entire tower.The failure analysis also give the suggestion that the butt welding joint of the internal supporting ring should not connect to the fillet welding joint between the ring and cylinder,then the break of the butt-welding joint can be prevented from spreading to the cylinder.