To　investigate　the　strength　design　of　the　plate-fin　heat　exchanger　header　with　lateral　nozzle,　the　calculation　procedure　of　limit　load　for　plastic　work　curvature　(PWC　)　criterion　by　using　ANSYS　and　Solidworks　is　presented,　the　limit　pressure　results　of　the　header　with　30　degree-lateral　are　compared　for　three　limit　pressure　criteria,　which　are　the　PWC　criterion,　the　twice　elastic　slope　(TES)　criterion　and　the　American　Society　of　Mechanical　Engineers　(ASME)　limit　load　criterion　of　perfect　plastic　material,　and　the　three　dimensional　parameters　affecting　the　limit　pressure,　which　are　the　lateral　oblique　angle　β,　the　ratio　of　header　diameter/header　thickness　i　Dδ,　and　the　opening　ratio　idD,　are　studied.　The　comparison　of　limit　pressure　results　for　the　header　with　30　degree-lateral　shows　that　the　PWC　limit　pressure　is　characterized　by　reflecting　the　structural　strengthening　effect　of　the　material　strain-hardening　on　the　header　by　using　the　plastic　work　and　the　plastic　work　curvature　as　the　global　indicators　of　plastic　collapse　mechanism,　which　is　objective　other　than　the　arbitrary　deformation　parameter　and　the　twice　elastic　slope　failure　line　of　TES　criterion;　the　relationship　study　of　limit　pressure　and　the　three　dimensional　parameters　shows　that　the　limit　pressure　is　decreased　with　the　smaller　lateral　oblique　angle,　larger　opening　ratio　and　larger　header　diameter/header　thickness　ratio.　The　research　results　can　provide　beneficial　guideline　for　calculating　the　plastic　limit　pressure　and　selecting　geometrical　dimensional　parameters　in　designing　the　plate-fin　heat　exchanger　with　lateral　nozzle.　©　2012　Journal　of　Mechanical　Engineering.