The detection of the weld position of steel pipes is a very important part of welding quality control and can be detected by a variety of methods. The following are some common weld position detection methods for steel pipes:

1. Visual inspection: Conduct a visual inspection of the welds of the steel pipes to check whether the welds of the steel pipes are at the designed position and whether they are offset or misaligned.
2. Dimensional measurement: Use measuring tools such as calipers, gauges, etc. to measure the size of the weld position of the steel pipe to ensure that the weld position of the steel pipe meets the design requirements.
3. Ultrasonic testing: Ultrasonic testing equipment is used to detect the weld position of steel pipes, which can detect the depth, position, and quality of steel pipe welds.
4. X-ray inspection: X-ray inspection equipment is used to detect steel pipe welds, which can display the position and internal structure of steel pipe welds, and is suitable for situations where high-quality requirements are required for steel pipe welds.
5. Magnetic particle inspection: Using the magnetic particle inspection method to detect the position of steel pipe welds, cracks, inclusions and other defects on the steel pipe welds can be found.
6. Optical fiber detection: Using optical fiber detection technology to detect the position of steel pipe welds, the position, and quality of steel pipe welds during the welding process can be monitored in real-time.

Choosing the appropriate testing method depends on factors such as welding materials, welding positions, and quality requirements. One or more methods are usually selected for comprehensive testing based on specific circumstances to ensure that the welding quality meets the requirements.