Pipeline welded joint design

In practical industrial application, line pipes are always welded to join together to form longer ones to meet the needs of engineering project. The welding joint is supposed to be as strong as the base material, not subjecting to fatigue, bending, crack or other defects.
The most commonly-used type of pipeline joint is butt joint, a process in which two pieces of pipes are joined together in the same horizontal plane. Butt welding has the advantage of good tolerance, high strength and less needed material. However, butt welding doesn’t mean the simple face-to-face connection of two pieces, which means the joining surface are not always vertical to the pipe plate. The edges of pipes are processed into different angles before welded, that’s what called pipeline beveling.

What is pipeline beveled end and why use it

Beveled end, to put it simply, is a joint surface with a specific beveled angle. In fact, it is processed prior to the welding of two pieces of line pipes, an angle formed at the edge of the end of the pipe with the help of a beveling machine.
Its foremost use is to achieve the best butt welding joint. Some pipes, especially those with great wall thickness, are difficult to be welded together due to low penetration. Even if joined together, they may not be deeply and completely welded due to the great thickness, so potential welding defect remains. Thus, when both ends of the pipes are beveled to form an angle, the thinner walls make it easier for pipes to be jointed together. Some filler materials will be put in the beveled space. The bevels increase their contact area, guaranteeing a better and deeper welding effect. Besides, pipeline beveling can be used to deburr the cut ends, making the pipes neat and tidy.

Common types of beveled ends and comparison among different types

Beveling ends can be made into various angles, achieving the better welding seam. Common beveled ends for butt joints are I-Type butt joint, single-V beveled end, double-V beveled end and single U-beveled end.
Beveled angle refers to the angle between the two beveled surfaces. Beveled face angle, normally used for single-U type, refers to the angle between the beveled surface and the vertical line to the pipe itself. The root opening refers to the gap between the roots of both pieces before welding, to ensure the roots get complete welding. The root radius for single-U beveled end is to increase the transverse space between the roots, making the welding reach the bottom of the root.

• I—type butt joint, also called square butt joint, is a relatively simple joint method for pipes of 1 to 6 mm in thickness. Strictly speaking, it is not a beveled end joint, for it only requires parallel matching the edges of two pieces together without certain angles. It is easy and economic to process, but is not recommended for pipes of thick walls.  As for thicker wall pipes, the angle of the bevel ends needs full consideration, trying to use the least filler metal material to provide the desired welding soundness.
• Single-V beveled end, is the most widely-used butt joint type in pipeline application. It suits pipes with the thickness of 3 to 26 mm. The beveled angle should be approximately 40 to 60°. Single—V beveled end is processed by a beveling machine. Comparatively speaking, it is more costly and needs more filler material than the I—type butt joint, but the joint is much stronger than the square joint. The disadvantage of single-V beveled end is its easy subjection to angular deformation.
• Double-V beveled end, also called X—beveled end, is developed on the basis of single—V beveled end. It needs double-side welding, so the material needs to be turned over after welded one side and the preparation time is longer than the single-V beveled end. It can be used for pipes of thickness 12 to 60mm. For pipes of same thickness, a double—V beveled end requires less filler metal material, because there are two narrower V-joints compared to one wider single—V beveled end.
• Single-U beveled end is a one-side welding joint. It requires less filler metal material than double—V beveled end and is less subjective to deformation. However, due to the radian shape, it is more difficult to process than the former methods.

Anson provides you pipelines with beveled ends

Different types of beveled ends have different requirements on pipes and welding methods. As a professional pipeline supplier,
Tianjin Anson International Co., Ltd provides beveling service according to your requirement. Clients can choose pipes with the most suitable beveled ends before welding application to achieve better pipeline butt welding performance.