On-site Turning Services for Heavy Industry

We use our mobile machining equipment also to perform on-site turning for the paper and paperboard industry, wind farms, other power plants and shipyards. Turning can also be carried out at our engineering workshop.

By newly turning, for example, the rolls and cylinders of shaft journals by means of specialist orbital machining, we can repair the failed surfaces whilst they are static. We also turn flanges to straighten them in order to restore the impermeability of their sealing faces.

Examples of jobs we have performed for our customers:

-          Turning of rolls and cylinders

-          Turning of flanges and mating surfaces

-          Turning of shafts

-          Repair of steam turbines

-          Turning and grinding of the bearing housings of rotors and turbines

-          Turning of heat exchangers

Contact us for more details!

Precision turning of shafts, journals, rolls, cylinders and flanges directly on-site

PR Rolls provides specialised on-site turning services for large industrial machinery and rotating components. Using portable and orbital machining equipment, our specialists restore worn or damaged surfaces directly where the equipment is installed.

Our on-site turning capabilities cover shafts, shaft journals, rolls, cylinders, flanges, mating surfaces, turbine components, bearing areas and other large industrial components. Services are provided for pulp and paper mills, power generation, wind energy, shipyards, marine applications and other heavy industries.

By machining the component on-site, PR Rolls can often eliminate the need for extensive dismantling, heavy lifting and transportation to an external workshop. This helps customers shorten maintenance lead times, reduce downtime and extend the service life of existing equipment.

Turning can be combined with grinding, milling, measuring, coating and field balancing as part of a complete on-site repair project.

What is On-site Turning?

On-site turning, also known as in-situ turning, field turning or portable turning, is a precision machining process performed directly where the industrial component is installed.

Instead of moving a large shaft, roll or machine component to a conventional lathe, portable machining equipment is installed around or adjacent to the component.

PR Rolls can use specialist orbital machining technology, enabling worn shaft journals and other cylindrical surfaces to be machined while the component itself remains static.

Depending on the application, turning can be used to restore:

• Diameter
• Roundness
• Cylindrical geometry
• Bearing surfaces
• Shaft journals
• Mating surfaces
• Flange surfaces
• Critical dimensions
• Damaged or worn surfaces

This makes on-site turning particularly valuable for large, heavy and production-critical machinery that would otherwise be difficult or expensive to dismantle.

Why On-site Turning?

Wear and mechanical damage can gradually change the dimensions and geometry of rotating components.

Shaft journals, bearing areas, rolls and other cylindrical surfaces must maintain the required dimensions and geometry to function correctly with bearings, seals and connected equipment.

Typical problems requiring turning include:

• Worn shaft journals
• Damaged bearing surfaces
• Scoring and surface damage
• Corrosion
• Diameter deviations
• Out-of-round surfaces
• Damaged flange faces
• Poor mating surfaces
• Sealing problems
• Mechanical damage following bearing failure

Precision turning removes damaged material and restores the component to the geometry required for repair, assembly or continued operation.

Typical On-site Turning Applications

PR Rolls has experience in a broad range of industrial turning applications. Documented examples include:

• Roll and cylinder turning
• Shaft turning
• Shaft journal turning
• Flange turning
• Mating surface turning
• Steam turbine repairs
• Rotor and turbine bearing area repair
• Turning and grinding of bearing areas
• Heat exchanger turning

The exact machining method is selected according to the component, damage, dimensions and operating requirements.

Shaft & Shaft Journal Turning

Restore worn journals without removing the shaft
Shaft journal turning is one of the most valuable applications for portable on-site machining.

Bearing failures, insufficient lubrication, contamination, corrosion and long-term operation can damage a shaft journal or bearing area.

Depending on the damage, replacing the complete shaft may be unnecessary.

PR Rolls can use specialist orbital machining equipment to machine the damaged surface while the shaft remains static. This allows the journal to be restored directly at the customer's site.

A typical repair may include:

• Inspection of the damaged journal
• Dimensional measurement
• Assessment of the repair method
• Installation and alignment of orbital machining equipment
• Precision turning
• Grinding or finishing where required
• Final measurement and verification

This approach can significantly reduce the dismantling and logistics associated with conventional workshop repair.

Orbital Turning

Traditional lathe machining normally requires the workpiece to rotate.

For very large installed components, this may be impossible or impractical.

Orbital turning reverses the principle: specialised machining equipment travels around the stationary component while the cutting tool machines the cylindrical surface.

PR Rolls uses this method to repair surfaces such as shaft journals while the component remains static.

Orbital machining is particularly suitable when:

• The shaft cannot easily be removed
• The component is too large for practical transportation
• The workpiece cannot be rotated
• Maintenance time is limited
• Machining must be performed in the installed environment

This creates an important alternative to complete component removal or replacement.

Turning of Rolls & Cylinders

PR Rolls performs on-site turning of large rolls and cylinders used in industrial production machinery.

Roll and cylinder surfaces, journals and other cylindrical areas can become worn or damaged during operation.

Depending on the application, turning can restore:

• Diameter
• Cylindrical geometry
• Journal dimensions
• Bearing areas
• Damaged surfaces
• Machining references

For pulp, paper and board industry applications, turning can form part of a wider roll or cylinder restoration project involving measurement, grinding, coating or balancing.

Flange Turning & Flange Face Restoration

Flanges depend on accurate mating surfaces to create reliable seals.

Corrosion, erosion, distortion and mechanical damage can compromise the flange face and lead to leakage.

PR Rolls provides on-site flange turning and mating surface machining to restore these critical surfaces. PR Rolls specifically uses flange turning to straighten surfaces and restore sealing performance.

Typical applications include:

• Worn flange faces
• Damaged mating surfaces
• Corroded sealing surfaces
• Distorted flanges
• Steam system components
• Process equipment
• Large industrial pipe and equipment connections

Restoring an existing flange can often be significantly faster than replacing a large component.

Turbine & Rotor Turning

PR Rolls has experience in steam turbine repair as well as turning and grinding of bearing areas on rotors and turbines.

Power generation equipment requires precise geometry and dimensional accuracy, particularly around shafts, journals and bearing areas.

Damage can occur due to:

• Bearing failures
• Wear
• Scoring
• Corrosion
• Lubrication problems
• Mechanical damage

Portable turning allows selected surfaces to be restored at the power plant during an outage or overhaul.

Where necessary, turning can be followed by precision grinding to achieve the required final geometry and surface condition.

Turning of Bearing Areas

Bearing areas and journals are among the most dimensionally critical surfaces in rotating machinery.

Wear or damage can affect:

• Bearing fit
• Shaft alignment
• Load distribution
• Vibration
• Equipment reliability

PR Rolls can machine worn bearing areas using portable turning equipment and combine turning with grinding where the final surface specification requires it.

PR Rolls' documented experience includes combined turning and grinding of rotor and turbine bearing areas.

Heat Exchanger Turning

PR Rolls also performs turning work on heat exchangers.

Heat exchangers and related process equipment can contain large mating, sealing and cylindrical surfaces that require accurate machining during maintenance or repair.

On-site machining enables critical surfaces to be restored without transporting the complete equipment to an external workshop.

This can be particularly valuable during plant shutdowns where maintenance schedules are tightly controlled.

On-site Turning for Power Generation

Power generation is an important application area for PR Rolls' turning capabilities.

Typical components can include:

• Turbine shafts
• Rotor bearing areas
• Shaft journals
• Flanges
• Mating surfaces
• Generator components
• Heat exchangers

PR Rolls' documented turning experience includes steam turbine repairs and rotor/turbine bearing areas, while its wider on-site machining services cover power plants and other large industrial equipment.

Portable machining enables repairs to be integrated into planned outages without unnecessary transportation of large components.

On-site Turning for Wind Energy

PR Rolls provides on-site turning services for wind farms and power generation applications.

Large wind turbine components can be difficult and costly to dismantle and transport solely for machining.

Portable turning technology allows suitable components and surfaces to be repaired in their installed environment, reducing logistics and supporting faster maintenance execution.

Depending on the repair, turning may be combined with measurement, grinding or other machining operations.

On-site Turning for Pulp, Paper & Board

Pulp, paper and board mills contain numerous large rotating components where accurate dimensions and surface geometry are essential.

PR Rolls' turning capabilities include rolls, cylinders, shafts, shaft journals and other critical rotating components.

Typical applications can involve:

• Roll journals
• Cylinder journals
• Large shafts
• Bearing areas
• Rolls and cylinders
• Flanges and mating surfaces

Turning can also be integrated into larger restoration projects where components subsequently require grinding, coating, measuring or balancing.

On-site Turning for Shipyards & Marine Industry

PR Rolls also provides turning services for shipyards and marine applications.

Large shafts, journals and flanges in marine equipment can be particularly difficult to remove for workshop machining.

Portable and orbital machining can reduce the need for:

• Extensive dismantling
• Heavy lifting
• Component transportation
• Extended vessel downtime

This makes on-site turning a practical solution for suitable repairs during planned maintenance, dry-docking and overhaul projects.

Precision Measurement Before Turning

Successful turning begins with understanding the actual condition of the component.

Before machining, PR Rolls can measure the damaged or worn area to determine the required repair scope.

Depending on the application, measurements may include:

• Diameter
• Roundness
• Runout
• Cylindrical geometry
• Surface damage
• Dimensional deviations
• Machining reference points

These measurements help determine how much material needs to be removed and establish the target dimensions for machining.

Verification After Turning

After machining, the component can be measured again to verify the achieved result.

Depending on the project, final verification may include:

• Diameter
• Roundness
• Geometry
• Dimensional accuracy
• Surface condition
• Alignment to reference points

Measurement and verification are an important part of PR Rolls' broader on-site machining process.

Turning & Grinding – Combined Surface Restoration

Turning and grinding are complementary machining processes.

Turning is particularly effective when larger amounts of damaged or worn material need to be removed and the component geometry must first be restored.

Grinding can then be used where a finer surface finish or more precise final surface condition is required.

A combined repair could therefore include:

Measurement → Turning → Grinding → Final Measurement

PR Rolls already performs projects involving both turning and grinding, including bearing areas on rotors and turbines.

Having both capabilities within the same service organisation can simplify complex industrial repair projects.

On-site Turning During Planned Shutdowns

Large industrial maintenance projects are often constrained by tight shutdown or outage schedules.

Removing a large shaft, rotor, roll or cylinder solely for workshop machining can add significant time for dismantling, lifting, transportation and reassembly.

On-site turning can reduce these requirements.

Key benefits include:

• Reduced dismantling
• Less heavy lifting
• Reduced transportation
• Shorter maintenance lead times
• Repair of stationary components
• Machining directly in the installed environment
• Coordination with other maintenance activities
• Faster return to operation

PR Rolls' overall on-site machining concept is specifically designed to restore large and difficult-to-move equipment at the customer's premises.

Planned Maintenance & Emergency Repairs

On-site turning can support both scheduled maintenance and unexpected equipment failures.

Planned Shutdowns
Restore worn shafts, journals, flanges and other components during scheduled maintenance.

Turbine & Generator Overhauls
Repair bearing areas, journals and other critical surfaces during planned outages.

Equipment Rebuilds
Restore or modify existing components as part of machinery modernisation.

Bearing Failure Repairs
Machine damaged journals and bearing areas following a bearing failure.

Emergency Repairs
Restore production-critical components when removal and workshop repair would result in excessive downtime.

This flexibility makes portable turning particularly valuable for large industrial machinery where production availability is critical.

Our On-site Turning Process

1. Inspection & Assessment
The component, damage and technical requirements are evaluated.

2. Precision Measurement
Existing dimensions and geometry are measured and machining references established.

3. Repair & Machining Plan
The required material removal, target dimensions and machining method are defined.

4. Equipment Installation
Portable or orbital turning equipment is installed and accurately aligned around the component.

5. Precision Turning
The damaged or worn surface is progressively machined to restore the required geometry.

6. Grinding or Finishing
Where required, turning is followed by grinding or another finishing process.

7. Final Measurement & Verification
The finished component is measured to verify that the required dimensions and geometry have been achieved.

More Than Turning – Complete On-site Machining

Turning is often only one part of a complete industrial repair.

PR Rolls provides a broad range of specialised on-site machining and maintenance services, including:

• Turning
• Grinding
• Milling
• Drilling
• Grooving
• Measuring
• Coating
• Field balancing

This allows PR Rolls to address several aspects of the same component during one maintenance project.

For example, a damaged shaft journal may first be measured and turned, followed by grinding and final dimensional verification. A roll or cylinder may require turning followed by grinding, coating or balancing.

Combining several operations can reduce the number of contractors involved and help shorten the total maintenance schedule.

Why Choose PR Rolls for On-site Turning?

PR Rolls combines specialised portable machining technology with extensive experience in repairing large industrial machinery directly at customer sites.

Customers benefit from:

• Specialist orbital machining capability
• On-site shaft and journal turning
• Roll and cylinder turning
• Flange and mating surface turning
• Steam turbine repair experience
• Rotor and turbine bearing area machining
• Heat exchanger turning
• Portable equipment for large components
• Precision measurement and verification
• Combined turning and grinding capability
• Support for planned shutdowns and urgent repairs
• Experience across multiple heavy industries

PR Rolls' objective is not simply to machine a surface. We aim to restore the dimensions, geometry, fit and functional condition required for reliable operation.

Frequently Asked Questions

What is on-site turning?
On-site turning is precision machining performed directly where a shaft, roll, cylinder or other component is installed. Portable machining equipment is brought to the customer's site, reducing the need to remove and transport large components.

What is orbital turning?
Orbital turning uses specialised machining equipment that moves around a stationary component. PR Rolls uses this approach, for example, to repair damaged shaft journal surfaces while the component remains static.

What components can PR Rolls turn on-site?
PR Rolls' documented applications include rolls and cylinders, shafts, shaft journals, flanges, mating surfaces, turbine and rotor bearing areas and heat exchangers.

Can PR Rolls repair damaged shaft journals?
Yes. PR Rolls can use specialist orbital machining to restore failed shaft journal surfaces while the component remains stationary.

Can PR Rolls repair flange surfaces?
Yes. PR Rolls performs flange and mating surface turning to restore damaged or uneven sealing faces.

Does PR Rolls perform turbine repairs?
Yes. Steam turbine repair and turning/grinding of rotor and turbine bearing areas are among PR Rolls' documented turning applications.

Can turning and grinding be combined?
Yes. Turning can restore the main geometry and remove damaged material, while grinding can subsequently achieve the required final surface condition. PR Rolls performs both processes.

Which industries use PR Rolls' turning services?
PR Rolls' existing turning page specifically identifies paper and paperboard, wind farms, power plants and shipyards. Its broader on-site machining services also support pulp mills, steel mills and other process industries.

Restore Large Components Without Removing Them

Large industrial shafts, rolls, cylinders, rotors and flanges do not always need to be removed or replaced when critical surfaces become worn or damaged.

PR Rolls provides precision on-site turning and orbital machining services, restoring shaft journals, bearing areas, rolls, cylinders, flanges and other critical components directly at the customer's site.

By combining turning, grinding, precision measurement and other portable machining methods, PR Rolls helps industrial customers reduce dismantling, shorten maintenance downtime and extend the service life of valuable machinery.