A dome is a component of a container, connected to the cylinder by welding. Depending on the geometric shape, it can be spherical, elliptical, dish-shaped, hemispherical, conical, and flat, among others. Spherical, elliptical, dish-shaped, and hemispherical domes are collectively referred to as convex domes. In terms of welding, they are divided into socket-weld domes and plug-weld domes. They are used in various types of equipment such as storage tanks, heat exchangers, towers, reactors, boilers, and separation equipment. Materials include carbon steel (A3, 20#, Q235, Q345B, 16Mn, etc.), stainless steel (304, 321, 304L, 316, 316L, etc.), alloy steel (15Mo3, 15CrMoV, 35CrMoV, 45CrMo), aluminum, titanium, copper, nickel, and nickel alloys.