| 摘要 |
<p>A hollow spherical article is mfd. from a wrought metal tube which is placed in a shaped die and explosively formed to expand into the die. The die has two cylindrical portions, one either side of a spherical portion, which define diametrically opposed apertures in the spherical surface of the article. The expansion is effected using a series of single charges detonated in succession. The article may be removed from the die and annealed after each firing. Used for mfr. of ball valve internal spheres and outer casings. The original tube blank can be selected to have the necessary dimensions for easy connection to the pipeline system in which it is to be used. An internal sphere or ball may be produced by removing, e.g. by ma the opposing cylindrical portions. Because of the greater strength of wrought metals the article can have thinner walls. This results in a reduced requirement for a structural support system by a redn. in wt. The absence of porosity in the material reduces wastage.</p> |
