Test and Determine the Strength of Ferrule Joint Pipe Fitting

Abstract

The tube connections in the cooling system are joints where a sleeve is crimped on the tube and then the tube is fitted between a nut and connector to ensure a leak proof joint. Earlier the crimping was done manually but the joints leaked in the field. A hydraulic tool is now available for crimping. The ability of the joint to prevent leakage depends on how well the sleeve 'bites' in the tube and how well the tube retains its original shape after crimping. These in turn depend on the (i) Material of the tube (ii) Material of the sleeve. Difference between the hardness of the sleeve and tube (with the sleeve being harder than the tube) Crimping pressure. Change in these parameters leads to different depth and amount of 'bite' and the extent to which the tube retains its original shape. A measure of the strength of the crimped joint is the amount of axial force needed to 'Pull Out' the sleeve after it has been crimped onto the tube. To create a variety of crimped joints where the parameters were varied. The size of the tube and thus that of the sleeve was not varied in order not to introduce additional variance in the parameters. A test set up to be created to hold a tube with both ends having a crimped joint in a tensile testing machine.