Theoretic Study on Influence by Machining Ovality of Premium Connections

Studied here in the article is the influence by the machining ovality of the premium connection on the make-up torque thereof by means of the Area Method and the Stress Integration Method. As a result the two related impact factors,i.e.,the ovality area impact factor k_S and the ovality stress integration impact factor k_F are worked out via computation,and then verified by living examples. It is regarded via the analysis that comparatively the Stress Integration Method is more suitable for measuring the influence by the premium connection superficial characteristic machining ovality on the connection make-up tight fit. And accordingly it is suggested that the ovality range of the air-tight premium connection be determined as half of that as specified under API Spec 5B—2017.