Interchangeability: What it Means

AGA XH0202This manual was originally published in 1984 with some 23 pages of text and 4 Apendices, including two on Fortran program language. The two appendices related to Fortran have been deleted from this reprinting. It still contains appendices on Derivation of Pressure Drop Index (PDI) and Research Paper 2193 by Elmer Weaver on Formulas and Graphs for Representing the Interchangeability of Fuel Gases.