METHOD FOR INSPACTION OF DEGREE OF WEAR OF TAPER JOINT PARTS THREAD (MODIFICATIONS) Russian patent published in 2006 - IPC G01B3/36 

FIELD: methods for inspection of the total degree of wear of taper joint parts thread.

SUBSTANCE: the method (the first modification) consists in the fact that the threaded surfaces of the coupling and nipple pieces under inspection are matched, their axial clamping and turn of one of them relative to the other towards unscrewing up to a jumpwise axial motion of the piece, is accomplished, the setting space between the end face of the coupling piece and the specific standard measuring plane of the nipple piece is measured, the total degree of the thread wear is determined. After measurement of the setting space in addition a test screwing together of the pieces is performed until the standard torque is attained, the final test space between the mentioned coupling components is measured, and the total degree of wear of the thread pieces is determined by the actual difference between the measured setting and the final test spaces. The second modification consists in the fact that additionally, at least once, the setting and final test spaces for a pair of a standard nipple and coupling are measured the standard difference of the mentioned spaces is determined, and the total degree of thread wear is determined by the difference of the actual difference and the standard one.

EFFECT: enhanced quality and reliability of inspection of the state of the thread of the threaded joint pieces by means of estimation of the degree of deficiency to the standard value of the mean diameter of thread in addition to the known estimation of the thread diameter variation by the profile tops; obtained more accurate conditions of classification of the thread state.

7 cl, 2 dwg