Induction Bending

Capability and Capacity

At Barnshaws, we offer a uniquely comprehensive induction bending service, providing the following decisive advantages: -

• Induction pipe bending from 50.8mm (2”) to 813mm (32”) O/diameter, using material up to 50mm thickness.
• Pipe and other sections can be curved to smaller radii than with cold bending techniques.
• Pipe surface unaffected/unblemished by the process.
• Multiple bends possible on a single length of pipe.
• Reduced welding requirement with compound bends, improving finished pipework integrity.
• Faster and more energy efficient than traditional fire/hot slab bending methods.
• A completely controlled and recorded process.
• Certification available, describing all key aspects of the induction bending process at a component-specific level, if required.

To ensure the most cost effective and efficient material usage, we provide a material utilisation pre-order analysis. This assists our customers in achieving unrivalled competitiveness and giving them a true edge in the markets they serve.

We can bend pipe from 50.8mm (2”) to 813mm (32”) O/diameter, using material up to 50mm thickness.

Barnshaws has also amassed a wealth of expertise in bending construction beams and 500 x 300 RHS, using this highly capable and versatile technique.

We induction bend with the following materials (list not exhaustive): -

Carbon steel – Alloy Steel (low, medium, high), Chrome, molybdenum steel – Case hardened and tempered steels – Heat resistant and high temperature steels – Low temperature steels – Stainless steel and acid resistant steel – Super Duplex stainless steel – Clad carbon steels (internally clad), Tubes and pipes, either seamless or welded.

Types of bend include: -

Quarter 90° bend – Angle bend 0-120° – SHS up to 400 x 400 x 20 – Cross over bend – S-bend/offset bend – RHS bent about minor axis up to 500 x 300 x 20 – Curved tube up to 813 – Elliptical tubes (minor and major axis) – Universal beams

Our full range of post manufacturing processes, associated with induction bending, includes: -

Weld preparation – Hydrostatic pressure testing – Heat treatment and cleaning – Coating and surface treatments – In house/third party inspections as applicable, inc. NDT testing – Mechanical and non-destructive testing.

Product RangE

Our 120,000 sq. ft. purpose built manufacturing facility houses 25 overhead cranes with a maximum lifting capacity of 20 tonnes. Our induction bending machines enabling us to bend from 2"NB to 32"OD. We can accommodate wall thicknesses from 2mm through to 50mm.

Materials suitable for Induction Bending include: -

• Carbon steels including API 5L Gr. B / ASTM A106 Gr. B
• Case hardened and tempered steels
• Duplex & Super Duplex steels, including 22% Cr (UNS S31803) and 25% Cr (UNS S32750 / 60)
• High chrome materials, inc. ASTM A335 P11, P22 & P91 etc.
• High yield steels - API 5L X42 to X80 (inc. internally clad steels)
• Low temperature materials, such as ASTM A333 Gr.6
• Specialist steels, including AISI 4130, Inconel, Hastelloy & Ovako 280®
• Stainless steels – ASTM A312 304L, 316L, 321 etc.
• Tubes and pipes, either seamless or welded

We can also carry out the following operations: -

• End Beveling
• Chemical cleaning, pickling & passivation
• Cutting of up to 32″ OD round sections   
• Destructive mechanical testing using our UKAS accredited laboratory partner
• Non destructive testing carried out by ASNT / PCN level II approved operators

How does induction bending work?

Induction bending is an advanced metal bending process, offering optimum precision, efficiency and consistency. It is suitable for a very wide range of applications and completely overcomes the potential limitations of cold bending techniques, such as distortion and wall thinning.

Straight pipe, tube or other section types are placed on a machine bed with a swing arm set to the required radius. The material is then hydraulically pushed through an induction coil at a carefully controlled and monitored rate. Heat of approximately 1000°C is solely focused on the area which requires bending, while cool air and water is sprayed on the area adjacent to the heated zone.

The combination of speed, heat and cooling allows sections to be bent to tighter radii without cross sectional deformation.

The machinery design ensures there are no limitations on the length of pipe used. The heat band eliminates the risk of pipe wrinkling and normal bending is carried out without the use of mandrels or formers, thanks to the robust support provided through the cooled pipe on either side of the narrow heated section.

Induction heating affords high speed and efficiency and enables very accurate temperature control (+ or - 30 degrees C). Pipes do not develop scaling during the process and even previously scaled material can still be bent as efficiently as pipe or tube in perfect condition. This remarkable flexibility also extends to previously rusted, seam, butt or spiral welded material.

Varying material wall thickness can also easily be accommodated, using appropriate machinery adjustments during manufacture.

Advantages of using induction bending

• Infinitely variable bend radius, offering optimum design flexibility.
• Superior quality in terms of ovality, wall thinning and surface finish.
• Avoids the need for components with an elbow, allowing cheaper, more readily available straight materials to be utilised.
• A stronger end product than elbows with a uniform wall thickness.
• Large radius bend capability reduces friction and wear.
• Surface quality of bent material is not relevant in terms of suitability for use.
• Quicker production times than the welding of separate components.
• No cutting, rounding-up, match boring, fitting or heat treating/welding of forged fittings.
• Pipe and other sections can be curved to smaller radii than with cold bending techniques.
• Material surface unaffected/unblemished by the process.
• Multiple bends possible on a single length of pipe.
• Reduced welding requirement with compound bends, improving finished pipework integrity.
• Welds avoided at critical points.
• Less need for non-destructive testing, driving costs further down.
• Faster and more energy efficient than traditional fire/hot slab bending methods.
• Process eliminates the need for sand filling, mandrels or formers.
• A clean, lubricant-free process.
• Bend specification changes are possible right up to the last minute before production.
• Reduced need for formal on-site inspection of welded joint integrity.
• Faster repair and maintenance lead times, due to relative ease of producing replacement induction-bent pipes or tubes.

Technical Information

OVALITY

Standard Wall Carbon Steel

Capacity

Barnshaws Group can bend pipe up to 813mm (32") outside Diameter.

THINNING

Standard Wall Carbon Steel

Capacity

Materials we can bend include:

• Carbon Steel
• Alloy Steel (low, medium & high alloy)
• Chrome, Molybdenum Steel
• Case Hardened & Tempered Steels
• Heat Resistant & High Temperature Steels
• Low Temperature Steels
• Stainless Steel & Acid Resistant Steel
• Super Duplex Stainless Steel
• Clad Carbon Steels (Clad Internally)
• Tubes & Pipes can be Seamless or Welded

Types of Bend

Barnshaws’ Experience

We have been deeply involved in induction bending since 1999. Since then we have amassed a vast amount of experience in all types of projects and applications.

Barnshaws' capacity range includes tubes up to 32" (813mm), rectangular hollow section up to 500 x 300, square hollow sections up to 500 x 500, beams up to 610 wide and channels up to 430 wide. No other company in the world offers such a range of sections / unusual forms.

The Barnshaws induction bending service is audited by SCCS to the ISO 9001:2015 standard. We work with SCCS on many pipe bending projects for third party approval.

Our in-house testing facilities include, ultrasonic thickness checking, surface hardness testing of the bend area and ovality / dimension reports and X-ray analysis.

Standard service for induction bending is 10 working days for small batches. No company can offer the same speed of turn around.

CE Marking

Barnshaws is the first metal bending company in the UK to have achieved total compliance with En1090-1; Requirements for conformity assessment of structural components, covering the supply of curved components to Execution Class 4 (Exc4). All our induction bent products are therefore fully CE marked for traceability.

Successfully assessed by SCCS, Barnshaws is able to assure customers that it has systems in place to ensure that all materials used in manufacture are correct for purpose, with a traceable audit path and that the Barnshaws product in question is fully compliant with its expected end use.

The CE Mark also confirms the competence, knowledge and skills of manufacturing staff and that manufacturing equipment is properly maintained and calibrated (where necessary).

Barnshaws invested a six-figure sum to achieve accreditation. Particular emphasis was placed on both the tensile and yield strength of products in the performance assessment of every aspect of the product range, using hundreds of samples fabricated to a variety of different radii.

The company has involved its entire supply chain in the CE Marking process, to ensure that all product components acquired from third parties are in full compliance in terms of measurement and performance.

All of Barnshaws’ five UK operations have been audited by SCCS during the accreditation process.

Post Bending Treatment

An inherent feature of induction bending is that mechanical properties may be altered – on occasions significantly - due to the heat input allied and the stresses applied during the process.

Most materials that have been induction bent by Barnshaws, in particular high yield carbon & duplex type steels, will therefore need a full body furnace heat treatment after bending in order to restore or improve mechanical properties. 

We offer the following post bending heat treatment services: -

Normalise

Most typically used for carbon steels such as ASTM A106 Gr. B, A333 Gr. 6 & API 5L X52, the normalising process involves a set time at temperature with a still air cooling to the ambient temperature away from the furnace area.

Normalise & Temper

Most usually applied to materials with a higher level of chrome e.g. ASTM A335 P11 & P22 etc. First we normalise the material, following this by tempering it for an extended period at a lesser temperature, again utilising still air cooling to the ambient temperature.

Quench & Temper

This post bending process is for high yield materials e.g. API 5L X65. We hold the material at temperature for a specified time. It is then quickly quenched in an appropriate cooling medium. This promotes a hardening action. We follow this by tempering at a reduced temperature with still air cooling to the ambient temperature.

Solution Anneal

A process that can be applied to stainless & duplex steels such as UNS S31803 & UNS S32760. We hold the material at a heightened temperature for a specified time. We then carry out a rapid cooling technique, using either air or water. Secondary heat treatment is generally not needed.

Applications

The numerous advantages of the induction bending process are now widely recognised and deployed across a diverse range of industries.

Induction bent pipes and tubes are typically used for anything from a large scale conduit to heat exchange and movement of a plethora of liquids and gases.

Bending by Barnshaws for structural applications meets N.S.S.S tolerances and conforms to ASME standards for petrochemical applications.

This remarkable application flexibility means that we are able to provide a full service to a wide range of industries, including (but not limited to): -

• Chemical
• Nuclear
• Compressor and pump stations - fluids and gases
• Construction
• General & Process Pipework
• Offshore Oil & Gas Production - subsea/topside
• Power Generation
• Petrochemical
• Shipbuilding

We would stress that new applications are being developed all the time. Please don't hesitate to contact us today to discuss how we can help you to deliver the many benefits of induction bending in new, innovative ways.