Medium wall reactors are vessels characterized by a reduced shell thickness. Stress rings are usually made from rolled plate, not from forgings. These products are used in processes where pressure and temperature do not reach extremely high values. In refinery plants, they are used for fluid catalytic cracking or continuous catalytic reforming; in fertilizer plants, they are used for urea production. Urea reactors are critical vessels because of the corrosive action of urea. Internals are fabricated completely in stainless steel following a sophisticated design with high-technology engineering solutions. Types of medium wall reactors are CCR reactors, FCC reactors, urea reactors, pressure vessels, & separators.