This work is about flexibility analysis of extraction piping of duplex heater which is situated in the neck of surface condenser. Extraction piping is comprises of six pipelines. Flexibility analysis is carried out by using analysis software CAESAR II for all six pipelines, out of which analysis of one pipeline is presented here in this paper. Analysis is done as per ASME B31.1-2014 power piping code. Pipe lines are designed as per piping isometric drawings. Input data such as pressure, temperature and thermal expansions at junction is given by the different department of company. Bellow properties are given by the vendors. Pipe lines are analyzed for sixteen different load cases which are sustained, operational, occasional and expansion types of load cases. Different stresses obtained after analysis are compared with allowable stress to check for the safety. The design is said to be safe if all the stresses are in allowable range as per code.

Keywords : Duplex heater; flexibity analysis; bellow; piping isometrics; thermal expansion.