Threaded connections

Abstract

In a threaded connection to be loaded in an axial direction, said connection comprising two pieces (i) having coincidental axes and (ii) having different coefficients of thermal linear expansion wherein one piece is a threaded male piece and the other piece is a threaded female piece, the improvement comprising providing, at ambient temperature, a taper such that the change in radial clearance per unit of length between the opposing threads of each piece is equal to the expression A.DELTA.T tan .theta. wherein: A = the difference in the coefficients of thermal linear expansion of the materials of which each piece is comprised, in the axial direction; .DELTA.T = the operating temperature of the connection minus ambient temperature; and .theta.= the acute angle formed by the loaded face of the thread of either piece with the axes, said radial clearance increasing in the direction of the loading of the piece having the higher coefficient of thermal linear expansion.

Dependencies are inferred from the claim text.