The strength-based design philosophy depending on the inherent ductility of structures is not suitable for lifeline structures like nuclear power plants where even non-structural damage is a severe safety problem. Design of supporting systems for pipelines carrying highly toxic or radioactive liquids is an important issue in the safety aspect for a nuclear power installation which is a key topic for researchers all around the world. Gener3ally, these pipeline systems are designed to be held rigid by conventional snubber supports for protection from earthquakes. The piping design must balance seismic deformations and other deformations due to thermal effect. A rigid pipeline system using conventional snubber supports always leads to an increase in thermal stresses; hence, a rational seismic design for pipeline supporting systems becomes essential. Contrary to this rigid design, it is possible to design a flexible pipeline system and to decrease the seismic response by increasing the damping through the use of passive energy absorbing elements, which dissipate vibration energy. This paper presents the experimental and analytical studies carried out on yielding type elasto-plastic passive energy-absorbing (PEA) devices to be used as support devices for pipelines subjected to large seismic deformations.