Head is a boiler, pressure vessel main pressure components, head of the boiler, pressure vessel main pressure components and the shape of the structure design is reasonable, affecting boilers, pressure vessels peace. Therefore, the relevant specifications of various head shapes have limitations. Dished head: that is dished head folding the spherical head. There is a large bending stress. Thus the use of the works is not ideal. Using dished head, and ellipsoidal head mainly film stress. Corner radius head transition region be not less than the inner diameter of head 10% and not less than three times the thickness of the head, sealing surface portion of the header should not be greater than the inner radius of the inner diameter of the head. No folding spherical punching head: no folding spherical head and cylinder of the junction obvious shape mutations. Therefore applies only to the smaller diameter, lower pressure vessel. With no folding spherical head, will produce large additional bending stress. The radius of the spherical head inside diameter shall not be greater than the cylinder body. Spherical head: boilers, pressure vessels convex head should adopt the spherical head. Its minor axis ratio of not greater than 2.5 the best selection of specification ellipsoid (Dnhn = 4) use of non-specification when ellipsoidal head. Carbon steel head in nitrates, ammonia, alkaline environment will occur, such as sodium crack head when the ordering instructions to eliminate residual stress. Austenitic stainless steel in a specific environment of chloride ion stress corrosion cracking occurs under, please select the appropriate materials in the design. Hot dip galvanized or aluminized need carbon steel container, please do the heat treatment to remove residual stress. I plant a variety of materials head to strict regime, exquisite technology, advanced equipment, perfect service dried up as the new and old customers with excellent products. Longwan Hongyu Metal Head Factory Add: Wenzhou City view golden sand town seven A Tel :0577 577 -86925750 -86925157 Fax Mobile: 13057722577 15355996788 Contact: Sun Shaodi URL: www.hyft.cn