Expanded PTFE Gaskets are made with Virgin PTFE and it has a multi-directional expansion.
It is a highly compressible material that can easily adapt to almost any kind of sealing surfaces, including damaged ones. It has the same chemical resistance as PTFE which makes it able to work with fluids range Ph 0-14 (except Fluorine and molten alkali metals). Its purity allows it to be in touch with food.
Its multi-directional structure helps substantially reduce runoff and loosening, retaining the torque.