Experimental study of the removable assemblies with screws from high pressure injection pumps

High pressure injection pumps use removable assemblies with screws. They allow the subsequent assembly and disassembly, without destroying the components and the entire assembly, whenever is necessary. Our paper is an experimental analysis highlighting the influence of tightening parameters on components deformations. We perform the study using controller, Janome screwdriver, ZEISS measurement system and SEM (Scanning Electron Microscope) used in the metallographic analysis. Various torques applied on the screws give us results that show the interactions and their impact on the pumps components, producing deformation on the screws, gaskets and even front plate. A trial was done to establish the upper limit for the torque of the screws. After applying several tightening’s at different values, we conclude that the optimal upper limit for screws tightening between front plate and housing is 45 Nm. Applying a torque bigger than 50 Nm, the screws are destroyed, shear. This can generate numerous defects on the sealing gasket area and on the front plate in the screws holes area. The circularity of the front plate is impacted by the thickness of the wall and the inner / outer diameters.