Analysis and Control of Fit Clearance between Main Bolt and Its Hole in Nuclear Reactor Pressure Vessel

When the main-bolt screws into the reactor pressure vessel,the fit clearance of the main-bolt and its hole is related not only to the speed value of the bolts and the alignment accuracy,but also the effective removing of the main-bolt and the damage of the hole surface.The selection of the main-bolt’s spinning-speed and the specific values of centering requirements are given by the quantitative analysis of dthe eputy thread fit clearance.In order to obtain a stable ideal thread pair fit clearance,we should control the manufacturing of the thread and optimize the assembly process.