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Precision metallic machining

We meet OEM and end‑user requirements for the highest level of precision machining of high performance alloys in the supply of proprietary components and standard items to exacting specifications for critical applications in industries including upstream and downstream oil and gas, nuclear energy, chemical and industrial gas production.

Backed by the latest technology and an ongoing commitment to training and development, our team has an unrivalled expertise in the machining of complex, thin-walled seals in a range of high specification alloys and titanium for use as primary barriers in high pressure applications.

These profiles are achieved time and again, reliably and repeatedly to the required concentricity thanks to our in-depth understanding of materials and machining processes.

All of our materials are fully certified and sourced from customer approved, specialist suppliers and we offer total confidence throughout the manufacturing process with rigorous inspection programmes and documentation.

Our long term working relationships with key OEMs coupled with our in-house expertise makes us a trusted partner for critical metallic seals and components.

We meet our customers’ expectations by providing the highest level of precision machining of high performance alloys and standard materials. We supply proprietary components and standard items to exacting specifications on a global basis.

Major operators and OEMs in the oil & gas sector have relied on our renowned engineering expertise and skilled workmanship for over 40 years in the production of API metal ring joint gaskets. The proven reliability of these items, displayed by their ability to operate the full oilfield life cycle, is at the heart of our success.

For the past 25 years, we have also manufactured proprietary components for the OEM market where innovation and long-term reliability are imperative. This has necessitated the development and implementation of special in-house machining techniques that enable us repeatedly to supply precision components from high-nickel and standard alloys.

From the first moment that you contact us - for standard or proprietary components - you will be dealing with members of a dedicated professional team who fully understand your requirements and know precisely how we can meet your demands.

The service we offer for the manufacture of proprietary components is assured, with highly skilled engineers and experienced staff responsible for every part of the operation. The stages that your component goes through are simple yet exceedingly thorough.

Assessment - Our product engineers study your CAD file or drawings, and select the most efficient and economical manufacturing method and routing.

Costing - We source material that meets your specification in a form that allows the most cost-effective manufacture, calculate the manufacturing methods and times, and factor in any post-machining processes (eg, NDT and coatings) before the quotation is issued.

Contract review - On receipt of your order, we check your Bill of Materials from QP to marking instructions, and countersign that all revisions on our manufacturing system are exactly in accordance with your latest specifications.

Materials - Where available, we immediately allocate stocked materials to the project, or order materials specifically for it. Special high performance alloys are sourced only from approved suppliers, primarily in Western Europe and North America. At receipt of material, dimensional and hardness checks are automatically conducted. Accompanying Mill Certification and documentation are reviewed against specification, then computer recorded and filed for reference.

Progress co-ordination - Your project is expedited and monitored through all machining stages via shop floor data capture, with intermediate inspection at all key phases.

Final in-house inspection - This is performed in accordance with your specifications by our Inspection Department using a combination of both traditional and the most advanced CMM equipment. Final hardness testing ensures that the specified level has been maintained.

NDT processes include ultrasonic testing, positive material identification (PMI), liquid penetrant inspection (LPI) and magnetic particle inspection (MPI).

PREN calculations, material grain size analysis, intergranular corrosion testing, and full verification of mechanical properties, are all available.

Third party inspection - When requested, we can provide inspection facilities and full documentation packages for your nominated independent inspectors.

Stock agreements - When required, we are prepared to hold stocks of your specified materials, or finished components, in readiness to meet your manufacturing or production schedules.

Documentation - Repeatability and sustainability of product quality is assured through a comprehensive documentation process covering every step from contract review to final delivery including necessary international documentation such as API, NORSOK, PED 97/23/EC, or GOST and incorporating full material traceability through every manufacturing process.

Our manufacturing and machining expertise is backed by exceptional documentation and quality control.

Bespoke quality plans are undertaken by our dedicated contract review and documentation team and can be supplied to API and NORSOK requirements, as well as integrated directly with online customer portals and completed to exacting customer specifications. A documented inspection before and after each manufacturing process ensures our customers have complete confidence in critical metallic seals supplied for industry’s most demanding applications.

As an OEM quality-approved supplier for critical components, our materials, products and processes are backed by full traceability and testing including:

  • Ultrasonic testing
  • Positive material identification
  • CMM inspection and profile scanning
  • Liquid penetrant inspection
  • Magnetic particle inspection
  • Material and final component hardness testing
  • Grain size analysis and inter-granular corrosion testing

Every component we manufacture can be traced back to the original batch of metal and a specific billet. Our computerised records that follow each machined item contain:

  • Mill Certification and heat treatment documentation from the material supplier
  • Our in-house hardness test verification results for that batch of material
  • Which machines were used to manufacture the component
  • In-house dimensional report from our Inspection Department
  • Final hardness test results, to ensure that any work hardening has not exceeded customer specifications
  • Full details of any post machining annealing, coating or NDT work undertaken
  • Third party inspection results, to customer’s specification, as required

To back up our manufacturing and quality processes we have invested in the latest measuring technology to ensure our products meet and exceed the most exacting standards. Our 3D coordinate measuring machines are capable of measuring complex profiles to an accuracy of 1.7 μm and even include temperature variation compensation.

Even on our most complex components, these machines can map the exact profile, store the detail, compare the results with the original drawing and then print a report in a fraction of the time that the most experienced quality inspector would require just to carry out an initial inspection. We can also feed the results obtained by CMM scanning directly back to our CNC machining centres, providing instant adjustment to machining processes on the next component if required.

Thin-wall machining - The need for precision machined components in the oil & gas sector has increased substantially as exploration and production operations go deeper and into more demanding environments.

We has developed and perfected special manufacturing techniques for the precision machining of annular thin-walled components. This expertise prevents thin-walled components being crushed on the machine, whilst allowing precise profiles to be achieved repeatedly to tight tolerances and with absolute concentricity.

Many of these components are manufactured from high-nickel alloys that are notoriously difficult to machine and control. 

We are able to machine components in-house of sizes from 25 mm (0.98in) OD to 2300 mm (90.6") OD, and to a maximum depth of 250 mm (9.8").  

Metal-to-rubber bonding - Leveraging expertise in elastomer materials from other parts of the James Walker Group we manufacture versatile metal / rubber composite seals for a range of applications.

This capability utilises our vast range of our high performance elastomers, including nitrile (NBR), hydrogenated nitrile (HNBR), fluoroelastomer (FKM) and tetrafluoroethylene / propylene copolymers (FEPM).

Our highly developed proprietary bonding processes incorporate acid etch, phosphating and chemical cleaning of metal surfaces to achieve optimum bond strength.

We apply these techniques extensively in the manufacture of specialised oilfield sealing products for wellheads, chokes and valves.