A kind of head head includes a male head, cone shell, adjustable sections, flat cap and austerity mouth design. Convex head include: hemispherical head, oval head, dished ends and spherical cap-shaped head. From the perspective of the force from the convex head hemispherical head gradually bad, but the difficulty of making point of view, good manufacturing gradually. 2 heads manufacturing methods a) small head: overall shape; b) large and medium-sized head: first splicing molding - the most widely used, mainly for the requirements of the standard in terms of it; c) oversize head: due to factors such as transportation and open files requested, the first split forming, after welding together. Stitching head first coefficient of welded joints after stitching forming head, splice welds shall be 100% radiographic or ultrasonic testing, qualification levels to go with the device housing. Final shape of the weld detection level, the same proportion with the device housing, high waste. Example: If the device detects the casing is 20%, III qualified. That elliptical head and final weld seam stitching III also qualified weld joint factor of 0.85; if the device casing is 100% inspection, II qualified. That head and final weld seam stitching II also qualified weld joint coefficient is 1. So head stitching although 100% detected, but not the same quality level, to go with the device housing. But pay attention to process manufacturing process: The correct approach is: cutting (dash) - small plate makes up a large plate - molding - molding NDT If you do not do testing before it is wrong, can not guarantee after forming also qualified. That means the final NDT NDT. 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