What is EFW in piping? What is the standard for EFW pipe?

——Analysis of Electric Fusion Welding Process and Its Key Standards in Pipeline Manufacturing

EFW Welded Pipe Explained: Learn about the Electric Fusion Welding process for large-diameter pipes and key standards like ASTM A358, A790, & A312 for petrochemical, oil & gas, and industrial applications.

In pipeline engineering, EFW (Electric Fusion Welding) is an important welding process for manufacturing welded pipes. This process typically involves using an electric arc as a heat source to melt the edges of rolled steel plates, often with the addition of filler metal (welding wire) to form a continuous, dense longitudinal weld. Compared to resistance welding (ERW) without filler metal, the EFW process is particularly suitable for producing large-diameter and thick-walled pipes.

The manufacturing process for EFW welded pipes begins with forming the steel plates through roll bending (RBE). MTSCO employs advanced automated welding technologies, such as combining plasma arc welding (PAW) with tungsten inert gas welding (GTAW), to ensure a full and stable weld. With this technology, we can produce large-diameter welded pipes with an outer diameter of up to 3 meters.

The production and acceptance of EFW welded pipes must comply with a series of stringent international standards. MTSCO is proficient in multiple mainstream standards and can provide precise welded pipe solutions for various industrial applications, including:

ASTM A358: The core choice for large-scale industrial pipeline projects (such as petrochemical and power industries).

ASTM A790: Covers welded duplex stainless steel pipes, which are widely used in marine engineering, oil and gas exploration, and chemical transportation due to their excellent strength and resistance to chloride stress corrosion.

ASTM A312: One of the most widely applied standards for welded austenitic stainless steel pipes, suitable for conventional corrosion-resistant and high-temperature environments, commonly used in food processing, pharmaceuticals, and general chemical industries.

These standards specify in detail the grades, levels, heat treatment processes, and non-destructive testing requirements for steel pipes. MTSCO has established a strategic partnership with HUXIN Factory, which has over 35 years of manufacturing experience. Our welded pipe factory holds ISO/PED/AD2000/M650 certifications and is equipped with a 12-meter-long heat treatment furnace to ensure that welded pipes undergo complete annealing heat treatment. We strictly adhere to standards, conducting 100% radiographic testing on all welds, and support third-party inspections by SGS, TUV, and others to ensure the highest quality EFW welded steel pipe products for global customers.