Nishimura, Suyama, Inoue, Higuchi
# 1995 Edinburgh
This paper describes an evaluatio~i metl~od for elearofusion joint strer~gtl~ and a basic co~~cept for determination of suitable fusion jointing col~ditio~~s. Firstly, the concept for estimating electrofusion joint strength is indicated. As an experimental result, it was found that the optimum fusion range lay between the minimum and maximum allowable heating times. Secondly, a computer program "EPOK' which simulates the elearofusion pracess for an elearofusion joint including the gap closing between the pipe and the joint has been developed. Experimental verification and recent applications ,using 'EPOK" are sl~ownconcerning tile evaluation of the effect of cooling time reduction for g the quick backdidling before complete c u o l i ~ ~and calculation for a revision of the JIS on elecirofusion joint dimensions. Thirdly, the effect of pipe surface conditions on fusion strength for EF jointing on work site is discussed. Scraping the pipe surface is the most effeaive way to remove any deteriorated parts and dirt in order to obtain higher fusion jointing quality.