APG technique is short for Automatic Pressure Gelation Process. It was proposed by Ciba-Geigy company from Switzerland on 19th,June,1969.Till now, the APG technique is widely used in the electricity area, especially widely applied to produce instrument transformer, insulators, bushings, contact box, SF6 cover etc successfully, like ABB, Ritz, Koncar. In China, with the development of APG technique, more and more companies adopt APG technique instead of old low efficiency technology. It is large and medium-sized equipment, dimension of clamping plate is 1000*1000mm,length of upper and lower core-pulling stroke can be determined according to the product(it needs lower core-pulling foundation pit when the lower core pulling exceeds 300mm). It is mainly used for transformer, 12KV-1250A,3150A insulating cylinder, contact box, 40.5KV bushing, bending plate, upper and lower shell of SF6 insulating cover, etc