Q245R Oval Head

1. Large-mouth elliptical head splicing requirements; the carbon steel is first formed after the first slab, and the weld height of the weld that hinders the forming of the head should be polished and made flush with the base material before forming. The thickness after grinding shall not be less than the design thickness" and "the surface of the weld shall be allowed to be lower than the surface of the base metal, but shall not exceed 0.8 mm".

2. Elliptical heads are more common for medium pressure, and spin type heads are usually larger heads. First of all, what is the difference between the stamping type and the spinning type: the stamping is good, the head is broken, the size is guaranteed, but it is suitable for the small head. The spin forming is inferior, especially in the R section. The thickness is not uniform.

3. The metal in the heating zone of the elliptical head cannot be freely expanded due to the partition of the metal with a low ambient temperature. The head is not free to shrink due to the shrinkage of the surrounding metal after cooling. As a result, the partially heated metal has a tensile stress, while the other parts of the metal have a compressive stress balanced therewith. When these stresses exceed the yield limit of the metal, the seal will be deformed; when it exceeds the limit of the metal, the crack will occur.

4. The elliptical head depth is between the hemispherical and the dish-shaped head. For the requirements of the stamping equipment and the mold, the elliptical head is easier than the hemispherical head in the manufacturing difficulty, and is more difficult than the dish-shaped head. In recent years, the use of a spinning manufacturing process has facilitated the manufacture of a large-diameter elliptical head. Elliptical heads are widely used in medium and low pressure vessels because of their comprehensive properties.