The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1986
Filed:
Apr. 30, 1984
Gregory L Calhoun, Apollo, PA (US);
Michael G Brunner, Pittsburgh, PA (US);
Kevin L Fields, Pittsburgh, PA (US);
Other;
Abstract
Both an apparatus and a process for pulling tubes from a tubesheet with two relatively movable gripping means are disclosed herein. The apparatus of the invention is a tube puller which has upper and lower gripping means for gripping the section of the tube surrounded by the tubesheet. The two gripping means are mechanically linked together by means of an extendable connecting assembly. This assembly includes an outer sleeve where the lower gripping means is located, and a middle sleeve where the upper gripping means is located which is slidable a predetermined distance within the outer sleeve. In the process of the invention, a tube puller as heretofore described is inserted into the mouth of a tube. The lower gripping means is then engaged to the mouth of the tube. The upper gripping means is then engaged in a section of the tube beyond the tube mouth with the extendable connecting assembly in a contracted position. A pulling means including a hydraulic ram then applies a tensile force onto the lower gripping means in order to pull on the mouth of the tube and to plastically contract the outer diameter of the tube in the vicinity of the tubesheet. After such contraction occurs, the connecting assembly between the two gripping means extends to its maximum length, and the pulling means applies a tensile force to both the upper and lower gripping means. Both of the gripping means then coact to withdraw the tube from the tubesheet. The invention preserves the metallurgical properties of the section of tube between the two grippers, which is important when the tubes are being sampled for corrosion degradation.