On-site machining services

Precision machining directly at your site

PR Rolls provides on-site machining services for large rolls, cylinders and heavy industrial machinery. Our specialists restore critical components directly at the customer’s premises, helping mills and industrial plants reduce downtime, avoid unnecessary dismantling and keep production equipment in reliable operating condition.

On-site machining, also known as in-situ machining, field machining or portable machining, means that precision machining is carried out where the equipment is installed. Instead of removing large components and transporting them to a workshop, PR Rolls brings the machining equipment, tools and expertise to your site.

This approach is especially valuable when the component is too large, heavy or production-critical to move. It is also the preferred solution when machining work must be completed during a planned shutdown or after an unexpected failure.

On-site machining at a glance

PR Rolls helps customers restore worn, damaged or misaligned machine parts without unnecessary transport or extended production stops.

Our on-site machining services help you:

• Restore large installed components directly on site
• Reduce downtime during planned shutdowns and urgent repairs
• Avoid heavy lifting, transport and workshop delays
• Repair instead of replace critical machine parts
• Restore surfaces, shapes, alignment and critical dimensions
• Improve sealing, contact surfaces and machine reliability
• Combine machining with grinding, coating, measuring or balancing
• Extend the service life of rolls, cylinders, shafts and machine structures
  
  

When is on-site machining needed?

On-site machining is used when a machine part must be repaired, restored or modified in its installed position. It is often selected when removing the component would be expensive, slow, risky or technically impractical.

Typical situations include:

• Worn or damaged roll and cylinder surfaces
• Damaged shaft journals or bearing areas
• Uneven sealing faces or flange surfaces
• Leaks caused by poor contact surfaces
• Misalignment in machine beds, frames or mounting surfaces
• Surface defects affecting production quality
• Maintenance findings during planned shutdowns
• Time-critical repairs after equipment failure
• Large components that cannot be transported efficiently

For many industrial customers, the main benefit is simple: the machine can be repaired where it stands.

What PR Rolls can machine on site

PR Rolls performs on-site machining for large and demanding components used in paper mills, board mills, pulp mills, power plants, steel mills, shipyards and other process industries.

Typical components include:

• Rolls and cylinders
• Drying cylinders
• Yankee cylinders
• MG cylinders
• Calender rolls
• Shafts and shaft journals
• Bearing areas
• Flanges and sealing faces
• Machine frames and bed plates
• Division planes
• Support rings
• Drum pulpers
• Debarking drums
• Kilns
• Filters and large rotating equipment

Our on-site machining methods

On-site grinding

PR Rolls provides on-site grinding for rolls, cylinders and other industrial components where surface quality, shape and runnability are critical.

Grinding is used to correct surface defects, improve profile, restore geometry and prepare surfaces for further treatment such as coating. In paper and board production, a correctly ground surface can improve machine performance, doctoring, drying efficiency and product quality.

Typical grinding applications include:

• Drying cylinders
• Yankee and MG cylinders
• Calender rolls
• Coated rolls
• Sealing surfaces
• Bearing areas
• Support rings
• Large rotating components

For demanding surfaces, PR Rolls can also provide superfinishing to achieve a very smooth, high-quality surface.

On-site turning

PR Rolls performs on-site turning for large rolls, cylinders, shafts, flanges and mating surfaces. Turning is used when surfaces must be restored to correct dimensions, shape or fit without removing the component from the machine.

Typical turning applications include:

• Roll and cylinder turning
• Shaft and journal turning
• Flange turning
• Mating surface turning
• Bearing area repair
• Surface restoration of large rotating parts

On-site turning is especially useful when a component must remain installed and the repair must be completed within a limited maintenance window.

On-site milling

PR Rolls provides on-site milling for large machine structures and contact surfaces. Milling is used to correct unevenness, restore flatness and repair surfaces that affect sealing, alignment or machine stability.

Typical milling applications include:

• Machine beds
• Bed plates
• Mounting plates
• Division planes
• Frames
• Basic rails
• Crane rails
• Sealing surfaces
• Keyways and contact surfaces

On-site milling helps restore the accuracy and reliability of large industrial structures without transporting them to a workshop.

A structured process from assessment to verified result

For demanding on-site machining work, a structured process is essential. PR Rolls plans each assignment based on the customer’s equipment, operating conditions, shutdown schedule and technical requirements.

1. Assessment and scope definition
The project begins with an assessment of the component, damage, wear or production issue. PR Rolls defines the machining scope, suitable method, required equipment and expected result together with the customer.

2. Planning and mobilisation
The work is planned around the customer’s production schedule or maintenance shutdown. PR Rolls prepares the required mobile machining equipment, tools and specialists for the site.

3. On-site machining
The machining work is carried out directly at the customer’s premises. Depending on the need, the work may include grinding, turning, milling, honing, superfinishing or several machining operations during the same shutdown.

4. Measurement and verification
After machining, the result is checked and verified. Measurement and inspection help ensure that the agreed surface quality, geometry, dimensions or alignment have been achieved.

5. Return to operation
When the machining work has been completed and verified, the equipment can be returned to operation with less downtime than traditional workshop-based repair methods.

Planned maintenance and urgent repairs

PR Rolls supports both planned maintenance and urgent repair situations.

During planned shutdowns, on-site machining can be used to correct wear, restore surfaces and prevent future failures before they affect production. In urgent situations, PR Rolls can help restore damaged components quickly and reduce the operational impact of unexpected machine problems.

This makes on-site machining suitable for:

• Scheduled maintenance shutdowns
• Preventive maintenance
• Overhaul projects
• Emergency repairs
• Production-critical surface restoration
• Projects where dismantling would cause excessive downtime

On-site machining for paper, board and pulp mills

PR Rolls has strong expertise in the paper, board and pulp industries. Large rolls, cylinders and rotating machine components are critical to production quality, runnability and efficiency.

For paper and board mills, on-site machining can help improve:

• Paper and board quality
• Cylinder surface condition
• Roll geometry
• Machine runnability
• Doctoring performance
• Drying performance
• Maintenance efficiency
• Production uptime

Typical applications include drying cylinders, Yankee cylinders, MG cylinders, calender rolls, coated rolls, shafts, bearing areas and other critical paper machine components.

On-site machining for heavy industry

In addition to paper and pulp, PR Rolls serves several heavy industrial sectors where large equipment must remain reliable and efficient.

Power plants
On-site machining can be used for shafts, flanges, sealing faces, bearing areas, frames and other large components where accurate surfaces and reliable sealing are essential.

Steel mills
Steel mills often require machining of large rollers, bearing housings, frames, shafts and other heavily loaded components exposed to demanding operating conditions.

Shipyards and marine industry
Large shafts, flanges, frames and structural components can often be machined on site, reducing the need for complex dismantling and transport.

Process industries
PR Rolls also supports chemical pulp mills and other process industries where large machinery must be repaired safely, accurately and within tight maintenance schedules.

Combine machining with coating, measuring and balancing

In many maintenance projects, machining is only one part of the complete solution. PR Rolls can combine on-site machining with other specialised services, such as:

• Coating
• Grinding
• Measuring
• Balancing
• Surface preparation
• Inspection
• Maintenance recommendations

For example, a worn cylinder may first be measured and ground, then coated to improve wear resistance and service life. A rotating component may require machining and balancing during the same shutdown. By combining several services, PR Rolls helps customers reduce the number of suppliers, shorten maintenance time and improve the final result.

Why choose PR Rolls for on-site machining?

PR Rolls is a specialist in demanding on-site services for industrial rolls, cylinders and large machine components. Our work is based on practical field experience, mobile machining capability and a deep understanding of production-critical machinery.

Choose PR Rolls when you need:

• On-site machining specialists for large industrial components especially DD-washer
• Grinding, turning and milling expertise
• Services for rolls, cylinders, shafts, flanges and machine structures
• Support for paper, board, pulp and heavy industry
• Reduced downtime and less dismantling
• Mobile equipment for demanding site conditions
• Surface restoration, measurement and verification
• The ability to combine machining with coating and balancing

A reliable partner for planned shutdowns and urgent repairs

Benefits of on-site machining
On-site machining gives industrial customers a practical and cost-efficient way to repair large components without moving them from their operating environment.

Key benefits include:

• Shorter downtime
• Lower total maintenance cost
• Less disassembly and reassembly work
• Reduced lifting and transport needs
• Faster return to production
• Repair of large and heavy components in place
• Improved surface quality and machine reliability
• Longer component lifetime
• Better control during shutdown projects
• Reduced risk compared with transporting critical components