Spiral steel pipe

During the fabrication of longitudinal spiral welded pipes, weld‑seam processing is fundamental to the product. Weld‑seam treatments are generally categorized into three types. Below, we will examine the weld seams encountered during fabrication: 1) All welds in branch pipes; 2) Longitudinal seams in the pipe wall; 3) Circumferential seams of the pipe; 4) Closed circumferential seams formed by crimping; and 5) Welds between diaphragms and the pipe wall. When these welds are inspected using ultrasonic testing, the inspection rate is 50%; radiographic inspection yields a 5% inspection rate; and the quality requirement is B1.

Category:

Spiral steel pipe

Email:

Phone/WeChat:

Keywords:

Share to

Product Description

　　During the fabrication of longitudinal welded pipes, weld seam processing is fundamental to their production. Weld seam machining is generally categorized into three types. Below, we will examine the weld seams as they are processed:
　　1. Welds of longitudinal spiral welded pipes: all welds in bifurcated pipes. 2. Longitudinal seams of the pipe wall. 3. Circumferential seams of the pipe. 4. Pinch‑closed circumferential seams. 5. Welds between diaphragms and the pipe wall. If these welds are inspected by ultrasonic testing, the inspection rate is 50%; for radiographic testing, the inspection rate is 5%; the quality requirement is B1.
　　Category II: Longitudinal welded seams of spiral-welded pipes—namely, the pipe‑wall joints; the butt welds of water‑stop rings and stiffening rings; and the combined welds between these components and the pipe wall. When subjected to ultrasonic inspection, such welds shall be inspected at a random sampling rate of 50%, with a quality requirement of Grade B2 acceptance.
　　Welds of spiral welded pipes in the three categories: The welds of auxiliary components experience very low stresses and do not require shutdown of power generation or water injection during maintenance.

Our Advantages

Smart Manufacturing Capacity Advantage

13 automated pipe‑making lines and 4 anti‑corrosion production lines, with an annual output of one million tons of steel pipes; all large‑diameter sizes are produced in‑house, ensuring stable lead times for bulk deliveries.

Quality and Qualification Advantages

Comprehensive nondestructive testing conducted by an independent laboratory, with dual certification under API and national standards; a long-term approved supplier for central state-owned enterprises, and fully qualified to bid on engineering projects.

Comprehensive Service Advantages

Customized solutions covering the entire oil & gas, municipal, and water‑conservation sectors, offering end‑to‑end support from conceptual design through logistics and after‑sales service, with capabilities for both domestic and international trade exports.