High-frequency consumables for tube and pipe welding

Through-flow impeders (HTF) are the most widely used and cost-efficient option for induction tube and pipe welding. Coolant flows directly through the ferrite core, ensuring stable weld performance in small- and medium-diameter mills. Standard connections include SAE flare, ISO metric, NPT, BSP and quick-connect couplings for fast integration and easy changeovers.

Heavy-duty HTF impeders contain up to 50% more ferrite and reinforced casings for higher efficiency at increased power levels and lower frequencies. Hollow HTF versions provide internal clearance for ID scarfing, annealing or cable routing. Casing options include epoxy glass, Ferroglass™ for higher weld speeds, and S300 Weld Guard for maximum uptime in spume-heavy environments.

Cooling requirements

Clean, filtered coolant at approx. 3 bar (45 PSI) is recommended. High-power applications may benefit from a chiller. Gas cooling (e.g., nitrogen) is technically possible but typically impractical due to consumption volume.

Main benefits

• Proven, cost-efficient design for small–medium tube mills
• Heavy-duty and hollow versions for demanding applications
• Stable weld geometry: V-length, approach angle, strip edge presentation 
• Multiple casing materials to match production needs

Return-flow impeders (HRF) keep the bore dry, preventing coolant contamination — essential for galvanised and coated tubes. ENRX’s M4 design uses threaded casings and O-ring seals for leak-free reliability and easy servicing.

They are available in standard, heavy-duty (30–50% more ferrite), and thin-wall versions for smaller diameters. Casings include silicone glass composites and S300 Weld Guard for spume resistance, with ceramic or quartz options for extreme heat.

Cooling requires higher pressure than HTF — minimum 4 bar (60 PSI) with fine filtration and inlet temperatures below 25 °C.

Main benefits

• Dry bore prevents coolant contamination — ideal for galvanised tubes
• Durable M4 design with replaceable casings and O-ring seals
• Heavy-duty and thin-wall options maximise ferrite efficiency
• Reliable cooling with higher pressure and fine filtration

Hollow impeders provide internal clearance for scarfing tools, coating, annealing or cable routing. They are available in both HTF and HRF designs and should be specified with the smallest possible inner diameter to preserve ferrite mass and maintain welding efficiency. Casing options include epoxy glass, Ferroglass™ and S300 Weld Guard for demanding production conditions.

Main benefits

• Central space for ID scarfing, coating or instrumentation
• Available in through-flow (HTF) and return-flow (HRF) versions
• Durable casing options for all production environments
• Stable alignment when used with ENRX support systems

Impeder clusters provide an efficient, cost-effective solution for large-diameter pipe welding (127–610 mm). Multiple round or rectangular impeders are arranged to maximise flux density and stabilise weld geometry. ENRX’s Quick Change System enables fast replacement—often without cutting the pipe—reducing downtime and alignment issues. Flexible layouts and manifold assemblies ensure effective cooling and long service life.

Main benefits

• Cost-effective solution for large-diameter pipes
• Quick replacement reduces downtime
• Configurations for round, square and rectangular profiles
• Stable, repeatable weld geometry

Integral mandrel impeders provide stable support for ID scarfing and bead rolling up to 3” diameter. A reinforced tie-rod, precision bushings and optimised ferrite placement ensure stiffness and consistent alignment. Available in HTF and HRF designs, with 13–31 mm O.D. and extended lengths up to 1030 mm. Standard threaded tow rods ensure easy integration.

Main benefits

• Stable, accurate support for ID scarfing and bead rolling

• Durable tie-rod and bushing construction

• Maximised ferrite use in a limited space

• Compatible with standard threaded tow rods

Impeder support systems ensure correct positioning inside the tube mill, preventing casing wear, misalignment and unstable welds. ENRX systems include interchangeable adapters for HTF and HRF impeders, adjustable brackets and clamps for precise alignment, and stainless-steel support tubes or hanger blades for long assemblies. Manifolds, adapters and coaxial return-flow couplings ensure reliable, consistent coolant delivery.

Main benefits

• Prevents casing damage and weld instability
• Precise, adjustable positioning for all mill types
• Strong stainless-steel support tubes for long impeders
• Flexible adapter and manifold options for reliable cooling

Induction coils are critical to HF welding efficiency. ENRX coils are made from 99.9% oxygen-free copper with silver-brazed joints and optimised cooling for low resistance and long service life. Single- and two-turn designs are available in left-hand, right-hand, universal and parallel orientations. Split coil versions allow fast changeovers without cutting the pipe, reducing downtime and scrap. Flange-mounted coils are available for pipe diameters up to 660 mm (26”).

Main benefits

• Low-resistance copper and efficient cooling
• Flexible single- and two-turn designs
• Split coils minimise downtime and scrap
• Flange-mounted options for diameters up to 660 mm (26”)

Impeder casings protect ferrite cores and ensure stable performance under HF welding conditions. ENRX offers epoxy glass for general use, Ferroglass™ for higher weld speeds and wear resistance, and S300 Weld Guard with a low-friction, spume-resistant surface for maximum uptime in coated or galvanised tube production.

Main benefits

• Durable casing materials for all welding environments
• Ferroglass™ increases weld speed and wear resistance
• S300 Weld Guard reduces spume adhesion and downtime
• Available in standard and custom sizes

Effective cooling is essential for stable HF welding performance. Impeders and coils generate heat from magnetic flux, molten metal exposure and resistive losses. ENRX cooling systems use regenerative turbine pumps and stainless-steel filtration to maintain clean, consistent coolant flow. Optional magnetic trap filters capture fine metallic particles and protect critical components. CS-1 and CS-2 units deliver reliable pressure for both standard and high-capacity applications.

Main benefits

• Stable coolant flow improves weld quality and efficiency
• Lower energy consumption through effective cooling
• Extended impeder and coil lifetime
• Flexible pump and filtration options for different mill conditions

Scarfing removes external or internal weld bead to create clean, defect-free surfaces for downstream processes such as sizing, coating and inspection. ENRX offers a complete scarfing portfolio, including SNMX external inserts, internal carbide rings (42°/48°), heavy-duty Canticut systems for large pipes, and Duratrim edge scarfing for coil preparation. These solutions improve surface quality, production stability and tool life.

Main benefits

• Complete scarfing portfolio for tube, pipe and coil processing
• Clean, precise bead and edge removal
• Wide selection of inserts, rings and toolholders
• Higher yield, reduced rework and longer tool life