Pipeline　layout　is　a　significant　factor　influencing　an　area-wide　layout.　But　in　the　most　of　published　works,　piping　system　only　consists　of　the　one-to-one　connection　pipelines　with　constant　diameters.　In　addition,　energy　loss　is　sometime　ignored　in　previous　works.　In　this　work,　energy　loss　due　to　pressure　loss　and　heat　loss　is　taken　into　consideration　originally.　An　improved　method　is　proposed　to　design　an　industrial　area-wide　layout　considering　the　optimization　of　pipe　network.　The　pipe　length　of　steam　piping　is　optimized　based　on　Kruskal　algorithm.　The　diameters　of　steam　piping　are　piecewise　considered.　The　flow　rates　are　obtained　by　solving　a　linear　programming　(LP)　model.　The　problem　of　area-wide　layout　optimization　is　solved　by　genetic　algorithm　(GA).　Finally,　the　results　of　a　case　study　show　that　the　optimization　of　piecewise　steam　piping　can　reduce　the　total　flow　rate　and　energy　loss　of　all　branches　in　the　pipe　network.　©　2018　Institution　of　Chemical　Engineers