Pipes are the most delicate components in any process plant. They are also the most busy entities. They are subjected to almost all kinds of loads, intentional or unintentional. It is very important to take note of all potential loads that a piping system would encounter during operation as well as during other stages in the life cycle of a process plant. Ignoring any such load while designing, erecting, hydro testing,start-up, shutdown, normal operation, maintenance etc. can lead to inadequate design and engineering of a piping system. The system may fail on the first occurrence of this overlooked load. Failure of a piping system may ixigger a ~ominoef fect and cause a major disaster. This is the lesson from the infamous Flixborough disaster that everybody having anything to do with design, engineering, maintenance, operation etc. of a piping system must learn. It is not sufficient to do 99 right things and 1 wrong thing while designing a piping system. The end result would be disastrous. One must score a perfect 100 in piping system design.