Spiral welded steel pipe connection techniques

Spiral welded steel pipe, also known as SSAW pipe, is a welded pipe made of strip steel coil as raw material, extruded at room temperature, and welded by automatic double-wire double-sided submerged arc welding process. The quality of the joints in the construction of spiral welded steel pipes directly affects the connection strength and sealing of the pipelines. Here are some operating tips and key considerations for achieving a seamless connection without misalignment.
 
1. Material preparation
Ensure that the surface of the spiral steel pipe is smooth, free of rust, and free of grease pollution. Clean and remove debris and contaminants that may affect the quality of the fit.

2. Joint design

Choose the appropriate joint form according to actual needs. Common joint forms include flat mouth, oblique mouth, V-shaped mouth, etc. Choose the appropriate form according to the working environment and requirements of the pipeline to ensure the firmness and sealing of the connection.

3. Precise cutting
Use appropriate cutting tools to ensure accurate, even cuts. The precision of joint cutting directly affects the quality of the joint and the reliability of the connection.

4. Preheating operation
For thick-walled spiral steel pipes, preheating is a crucial step. Preheating improves the plasticity of the material and the welding performance of the joint. Carry out appropriate preheating treatment according to the thickness and specifications of the material to ensure the quality of joint welding.

5. Joint welding
Choose appropriate welding methods and process parameters. Common methods include manual arc welding, submerged arc welding, gas shielded welding, etc. Choose the appropriate method according to the specific situation, and strictly control parameters such as welding current, voltage, speed, etc. to ensure welding quality and joint firmness.

6. Detection and Repair
After the connection is completed, joint quality inspection is performed. Use non-destructive testing methods such as ultrasonic or radiographic testing to detect defects and inconsistencies in welds. Repair problems promptly to ensure joint integrity and connection reliability.

Other operating tips and precautions:

- Cleaning and deoxidation
Thoroughly remove grease, rust and contaminants from the joint area before welding. In addition, deoxidation is performed to prevent oxidation reactions in the joint area, which could affect the welding quality.

- Welding sequence
For longer spiral steel pipes, the joint area should be divided according to the actual situation and the welding sequence should be determined. A reasonable welding sequence can prevent welding stress concentration and deformation problems and ensure the flatness and firmness of the connection.

- Control heat input
Control heat input during welding to avoid excessive temperature and welding stress. Excessive heat input will cause joint deformation and cracks, affecting the connection quality. Control heat input through appropriate welding speed and moderate preheating to ensure welding quality and joint reliability.

- Quality inspection
After welding is completed, a comprehensive quality inspection is performed. In addition to non-destructive testing, visual inspection, dimensional measurement and other methods are also used to check the appearance quality, dimensional accuracy and weld integrity of the joints. Any issues are promptly repaired or reworked.

By following these operating tips and precautions, you can achieve high-quality, seamless joints of spiral steel pipe. Improve the quality of joints, ensure the safety, reliability and durability of the pipeline system, and promote the smooth progress of engineering projects.

Go here to learn more: Seamless pipe vs spiral pipe: what's the difference?