In the production of our "one piece forging valve," the head of the valve is forged under a slow two-step process to avoid damage to the material structure. The forging piece is then machined entirely to eliminate any imperfection from the forging operation. Next is triple heat treatment, the stress-relief process, the grinding, and then the coating. Finally the valve stem is rolled to remove the rough scale and any gross imperfection on the surface. Ultrasonic tests and x-rays are then performed piece-by-piece to give each part a certified quality.