封头设计中给出最小厚度的必要性

GB150-1998《钢制压力容器》和JB/T4746-2002《钢制压力容器用封头》规定：对于按规则设计的封头,成形封头实测的最小厚度不得小于封头名义厚度减去钢板厚度负偏差C1,因为封头名义厚度包含设计者按钢板规格向上圆整值,将造成封头人为增厚。增加了制造厂毛坯重量,影响了企业经济效益。因此提出在设计中给出封头设计的最小厚度（设计者考虑了圆整值）,并以设计者给出的封头设计的最小厚度作为封头成形厚度的最小值（成形封头实测的最小厚度）。

Necessity of indicating Min.Head Thickness in the Design

With regard to the head designed according to the Code,as specified in GB150-1998“Steel Pressure Vessel”and JB/T4746-2002“Head for Steel Pressure Vessel”,the actual min.thickness of the formed head shall not be less than the value derived from that head nominal thickness deduct plate thickness minus deviation C1.Because head nominal thickness contains round-off value specified by designer per plate siza,the head will be thicker due to that reason.It will cause havier blank weight and badly influence upon economic benefit.The article provides the min thickness shall be given in head desigh with consideration of round-off value,and such min thickness given by the head designer shall be considered as the min.value of the formed head,i.e.the actual min thickness of the formed head.