APPARECCHIO PER MANDRINARE E GUIDARE TUBI PARTICOLARMENTE PER SCAMBIATORI DI CALORE DI CENTRALI TERMONUCLEARI

摘要

A tube guide-expander for guiding heat exchanger tubes through tube sheet apertures from a secondary to a primary side thereof and expanding those tubes into contact with the apertures' walls. The guide-expander includes relatively axially displaceable first and second compression structures and elastomeric O-rings which radially expand into contact with the tube's inner surface when axially compressed between the compression structures. The first compression structure is abuttable with the tube's end and has an axial opening therethrough. The second compression structure constitutes an elongated element which extends through the opening and has a ram element connected to the end inside the tube and a driving element connected to the end outside the tube. The ram and elongated elements are preferably threadably engaged so as to permit relative axial displacement therebetween when they are relatively rotated. Such relative axial displacement maintains selected degrees of axial compression on the radially expansible O-rings and provides releasable retention of the guide-expanders in the tubes during guidance of the tubes through the tube sheet apertures.