The Effect of Transient Operation on Gasket Contact Pressure in Steam Generator Primary Side Obround Manway
The Steam Generators used in CANDU Nuclear Power Plants employ a primary-side obround manway design with two cover plates on each side of the opening. During transient operation of the units (heat up, start up, operation, shut down and cool down) a complex interaction between the manway components occurs, which not only causes time-varying gasket contact pressure but also induces a non-uniform gasket contact pressure along the gasket width. As a result, the leak tightness of the joint may be affected. The effect of different stud preloads on the gasket contact pressure during transient operation is investigated by the 3D FE Analysis of a primary-side obround manway of CANDU’s steam generator. The results are used to justify the seal performance of the manway structure under conditions of different stud pretension loads.