1. What is the difference between A53 and A106?
A53 includes both welded and seamless pipe for general service.A106 is mainly seamless for high-temperature service.
2. What is spiral welded pipe (SSAW)?
SSAW = Spiral Submerged Arc Welded pipe. It is made by spirally rolling steel plate and welding with submerged arc. Used for large-diameter pipes.
3. What is LSAW pipe?
LSAW = Longitudinal Submerged Arc Welded pipe. Made from steel plate, formed into pipe, then welded longitudinally. Used for large-diameter, high-pressure lines.
4. What is the purpose of normalizing ERW pipe?
Normalizing refines grain structure, improves toughness, reduces welding stress, and enhances mechanical properties.
5. Why is weld seam heat treatment needed?
It eliminates welding residual stress, improves ductility and impact resistance, and prevents cracking in service.
