Similarities and differences between SAWH & SAWL
Weld form and manufacturing process
SAWH (Spiral submerged arc Welding) :
The weld is coiled around the axis of the steel pipe. The hot rolled coil is used as the raw material and is continuously coiled and welded by the spiral forming process. This process allows the production of large diameter steel pipes (e.g., up to 508mm outside diameter).
SAWL (Straight seam submerged arc Welding) :
The weld is a straight seam parallel to the axis of the steel pipe, using a single sheet steel plate as the raw material, and welding after forming through the straight seam. Its production is limited by the width of the steel plate and is usually suitable for small and medium caliber steel pipes.
Materials and production efficiency
SAWH (Spiral submerged arc Welding) :
Hot rolled coil, high material utilization rate, suitable for continuous, mass production, especially suitable for long distance pipeline projects.
SAWL (Straight seam submerged arc Welding) :
The use of steel plate production, more flexibility, can be fixed size or double size production, suitable for the length of the specific requirements of the scene (such as the length of the allowable deviation of -0 to +50mm).
Mechanical properties and application scenarios
SAWH (Spiral submerged arc Welding) :
The spiral weld makes the steel pipe under internal pressure, the circumferential stress distribution is more uniform, and the pressure resistance is strong, which is often used in oil and natural gas long distance pipelines and large diameter low pressure fluid transportation (such as water and gas).
SAWL (Straight seam submerged arc Welding) :
The axial strength of straight welds is high, which is suitable for scenes with strict requirements on the straightness of welds, such as building structural support and short-distance high-pressure fluid transportation
Inspection and quality control
SAWH (Spiral submerged arc Welding) :
The length of spiral welds is long, and the continuity and uniformity of welds should be paid attention to when testing, usually ultrasonic or X-ray flaw detection.
SAWL (Straight seam submerged arc Welding) :
The detection of straight welds is relatively simple, but it is necessary to focus on checking the quality of the weld at the beginning and closing of the arc.
