According to the shape of the Groove, Groove into I-shape (without Groove), v-, y-shaped, double y-shaped, u-shaped, and u-shaped, single v-shaped, two-side y, j-shaped and other Groove. V and y-Groove machining and welding easier (do not turn), but prone to angular distortion after welding. Double y-shaped Groove is v-shaped Groove on the basis of development. When the weld thickness increases, double y-shaped instead of v-groove at the same thickness, you can reduce the amount of weld metal of about 1/2, and symmetric welding Welding residual deformation. To turn disadvantage is the welding process, welding inside the tubular Weldments, making working conditions worse. Amount of filler metal u-shaped Groove under the same conditions as in the weld thickness much less than the v-groove, but the Groove processing of less complex.