Learn about the 3 types of steel pipes used in the petrochemical industry: seamless, ERW (electric resistance welding), and LSAW (longitudinal submerged arc welding). A seamless pipe is manufactured by drawing a solid steel billet through a piercing rod. Welded pipes are produced by cutting, bending, welding coils, or steel plates.
Seamless Pipe
Seamless pipes are produced starting from steel billets, that are heated and perforated to create the tubular section. The word “seamless” means the absence of seam welds.
Seamless steel pipes are used for different applications within the oil & gas industry:
upstream operations (OCTG pipes)
midstream (transmission and distribution of fluids, as oil, gas, steam, acids, slurries)
downstream (process piping to refine oil and gas in derivative products)
general plumbing applications for utility services
The Most Common Types of Seamless Pipe Pipes:
1. ASTM A53, A106, A333, and API 5L (types of carbon steel pipes for high and low-temperature carbon steel)
2. ASTM A335 Grades P5 to P91 (chrome-moly alloy steel pipes for high temperature and pressure, for refinery and power plants applications)
3. ASTM A312/ A312/ A269 Series 300 and 400 (stainless steel pipes in grades 304, 316, 321, 347, 904L, 254SMO, 317L, etc.)
4. ASTM A790/ A789/ A928 (2205, 2507 with double ferritic and austenitic structure)
Various nickel alloys material specifications (Inconel 625, Hastelloy C276, Monel 400, Nickel 200, etc.)
ERW Pipe (electric Resistance Welding)
ERW pipes are manufactured using steel coils: the coil is first uncoiled, then smoothed, cut and, finally formed into a pipe shape by joining its two extremities electrically. ERW pipes are available in sizes between 1/2 and 20 inches, in ASTM A53 carbon steel pipe and ASTM A312 stainless steel pipe. In terms of dimensions, the ASME B36.10 and ASME B36.19 are the key reference specifications (API 5L for welded ERW line pipes).
LSAW Pipe (longitudinal Submerged Arc Welding)
An LSAW pipe (“submerged arc welding”) is manufactured by cutting, bending and welding steel plates (JCOE process). LSAW pipes compete with seamless and ERW pipes in the size range between 16 and 24 inches but are “must-go” option for pipelines above 24 inches (as 24 inches is the maximum size for commercial seamless pipes). The difference between LSAW and ERW pipes is that LSAW pipes are produced using steel plates, SS ERW pipes are manufactured starting from steel coils.
