The HFW Welding Process
High-frequency welded pipe is a type of steel pipe manufactured by instantly heating the edges of metal strip to welding temperature using high-frequency current, typically 100 to 450 kHz, followed by pressure welding through squeeze rollers. The skin effect concentrates the current at the strip edges, and the forged weld forms a sound metallurgical bond without filler metal. Inline heat treatment of the weld zone refines the structure for toughness.
Specification Range
Outside diameters range from 21.3 to 609 mm, about 1/2 to 24 inches, with wall thicknesses from 2 to 20 mm per schedules SCH10 to SCH40. Standards include API 5L, ASTM A53, A252, and A500, plus EN 10217 and EN 10296. Materials include X42, X52, X60, Q235B, Q345B, Gr.B, S275, S275J0H, S355J0H, and SS400. Lengths of 5.8, 6, 12, and 18 m fixed, or single and double random, are available.
Applications
HFW pipes are widely used in construction and manufacturing: outdoor piping in conjunction with scaffolding and steel frameworks for building construction and municipal infrastructure; low-pressure fluid transmission pipes for gases such as natural gas, air, and steam, and liquids; structural steel pipes in engineering structures and support systems; oil pipelines primarily used for drilling and oil extraction; and liquid transmission pipes mainly transporting petroleum and natural gas.
Quality and Testing
HFW pipe is verified by chemical composition, tensile testing, flattening, hydrostatic testing, and non-destructive examination of the full weld seam by eddy current or ultrasonic testing, with weld-line heat treatment ensuring the weld meets the toughness requirements of the applicable standard.
Selection Guidance
Select the standard by application: API 5L for line pipe, A53 for general plumbing and mechanical, A252 for pipe piles, and A500 for structural hollow sections. Confirm the grade, size, schedule, and testing requirements in the purchase order.
Frequently Asked Questions
Q: What is HFW pipe?
A: Pipe welded by high-frequency current at 100 to 450 kHz with squeeze-roller pressure, without filler metal.
Q: What is the size range?
A: OD 21.3 to 609 mm with walls of 2 to 20 mm.
Q: What standards apply?
A: API 5L, ASTM A53, A252, A500, EN 10217, and EN 10296.
Q: What materials are available?
A: X42 to X60, Gr.B, Q235B, Q345B, S275 to S355, and SS400.
Q: What NDT is applied?
A: Eddy current or ultrasonic examination of the full weld seam.
Q: What lengths are available?
A: 5.8, 6, 12, and 18 m fixed, plus SRL and DRL.
For HFW steel pipe quotations with your required standard and size, contact our sales team.
