With an objective of understanding the cyclic fracture, fatigue crack growth and ratcheting behaviour of Type 304 LN stainless steel piping components used in primary heat transport system of nuclear power plants, subjected to various operational, loading and environmental conditions, experimental studies were carried out on totally 36 straight pipes and eight elbows. The pipe dimensions were in two categories: 170 mm OD and 15 mm thickness or 324 mm OD and 25 mm  thickness. These studies on actual size piping components of power plants have resulted in very valuable fatigue behavior related data, which would form important inputs in assuring safety and damage tolerant design of power plan. An overview of the studies is presented in this paper.