Professional Analysis of Cement Pole Welding Procedures

In modern power grid construction, high-bending-moment, high-strength cement poles have become the mainstay of high-voltage transmission lines. For sectional poles of 18 meters, 21 meters, or even longer, steel ring welding serves as the "joint" connecting each section, and its quality directly determines the mechanical strength and service life of the pole. As a professional cement pole manufacturer, we will provide you with an in‑depth analysis of the entire precision welding process, revealing the craftsmanship behind quality poles.

I. Pre‑weld Preparation: Pole Alignment and Straightening

The first step of welding lies in precise alignment. The operation must be carried out on a level ground, where the lower section is properly placed and cushioned, followed by hoisting the upper section for connection. The core technique involves straightening and concentricity control: the steel ring interfaces of the two sections must be aligned and centered, leaving a 2–5 mm gap at the weld joint, with a misalignment deviation not exceeding 2 mm. At this stage, leveling instruments and theodolites are used for precision measurement to ensure the overall straightness deviation of the pole is controlled within 2‰ of its total length, which is the foundation for preventing uneven stress distribution.

II. Tack Welding: Fixation and Verification

Once straightening meets the standard, direct full welding is strictly prohibited. The correct approach is to apply three‑point or four‑point symmetrical tack welding evenly distributed along the circumference of the steel ring flange. This step acts as a "temporary riveting" that effectively resists stress deformation caused by thermal expansion and contraction during subsequent welding. After tack welding, a secondary straightening check is required, and only after confirmation can the main welding phase proceed.

III. Layered Welding: Symmetry and Continuity

High‑bending‑moment poles usually have steel ring thicknesses greater than 6 mm, necessitating a V‑groove multi‑layer welding process. The welding follows the principles of "symmetry, segmentation, and multiple layers":

Symmetrical cross‑welding: Two or more certified welders weld simultaneously at symmetrical positions, using segmented skip‑welding to disperse heat input and minimize welding deformation.

Multi‑layer welding: The entire joint requires three or more repeated welding passes. The first layer serves as the root pass to ensure full penetration, while subsequent layers are for filling and capping. After each layer, slag must be thoroughly removed, and the joints of adjacent weld beads must be staggered by more than 50 mm. Filling foreign matter into the weld seam is strictly prohibited.

IV. Post‑weld Treatment: Anti‑corrosion and Protection

After welding is completed and the joint has cooled naturally, slag is removed and the appearance is carefully inspected. A qualified weld should show a smooth, fine scale‑like surface, free from cracks, undercuts, porosity, and other defects. The final step is anti‑corrosion treatment: thoroughly clean the weld and surrounding areas of rust and mill scale, and apply a high‑performance anti‑rust paint evenly. Meanwhile, the drainage hole at the bottom of the pole should be cleared, and the top end sealed to prevent internal water accumulation and freezing damage.

We are located in Qufu, Shandong, and are a national high‑tech enterprise integrating R&D, design, production, and global supply of large‑scale concrete electrical products. We are committed to solving the complex coordination challenges in pole‑tower supporting systems for global power and communication projects, creating a "full‑category, one‑stop" procurement platform ranging from national‑standard poles to specialized components. Our products are exported in bulk to countries along the "Belt and Road," including Indonesia, Senegal, and Burundi, with our business footprint spanning Southeast Asia, Africa, the Middle East, and South America. With strong production capacity and stable bulk quality, we have earned the trust of multiple state‑owned power enterprises through long‑term repeat orders. We continue to contribute the strength of "Made in China" to global infrastructure development.