The sealing system is made up of a symmetrical U - shaped seal with two sides. It is assembled closely with the internal rigid insulating ring and is firmly squeezed in the reserved space between the forgings of the left and right flanges to achieve the best sealing effect. This seal system is designed for the insulation joint products. It is also the patent technology of the company. This system is usually referred to as "DSGS" (that is, double gasket system).