ERW (Electric Resistance Welded)
HFI (High Frequency Induction)
EFW(ELECTRIC FUSION WELDED TUBE)
LSAW (Longitudinal Submerge-arc Welded)  UO(UOE)、RB(RBE)、JCO(JCOE)
DSAW (Double Submerged arc welded)
SAW (Spiral Welded)
SSAW (Spiral Submerged-arc Welded)

Quality Standard: 
ERW HFI , EFW, LSAW, DSAW:
GB/T3091 Welded steel pipe for low pressure liquid delivery
GB/T9711 Petroleum and natural gas industries--Steel pipe for pipelines
IS: 3589 Steel tubes for water and sewage 
IS : 1978-1982  Steel tubes for use in transportation of oil; gas & Petroleum products 
BS: 1387 Steel Tubes for use for Water, Gas, Air and Steam
ASTM A53 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
DIN 2458 WELDED STEEL PIPES AND TUBES
EN10217 Welded steel tubes for pressure purposes. Technical delivery conditions. Non-alloy steel tubes with specified room temperature properties
API 5L Line Pipe