Tower
Flanges
Restore tower section flange flatness on-site. No re-fabrication, no transport.
Support Structures & Flange Solutions
Tower
How It Works Tower Flanges.
Tower Flanges.
Controlled Flatness.
Reliable Connections.
Tower flange flatness plays a critical role in the structural integrity and long-term performance of wind turbines. Even small deviations caused by the welding process can lead to uneven bolt preload, local gaps between flange surfaces, increased fatigue loading, and unnecessary maintenance throughout the turbine's lifetime.
CNC Onsite performs precision flange milling after welding, restoring tower flanges to the required flatness and geometry through controlled CNC machining. By replacing traditional heat straightening with a repeatable machining process, manufacturers achieve consistent tolerances while improving both quality and production efficiency.
Across multiple projects, CNC Onsite has consistently delivered flange flatness well below industry requirements, including results down to 0.21 mm global flatness. The controlled machining process ensures uniform contact surfaces, supports correct bolt tensioning, and contributes to reliable structural connections throughout the lifetime of the wind turbine.
Our flange milling solutions are integrated directly into fabrication environments, supporting efficient serial production while maintaining the precision required for today's large onshore and offshore wind turbines.
Technical Specifications
Typical duration 1–5 days on site
Diameter range Up to Ø10,000 mm
Flatness tolerance OEM specification
Certification ISO 9001
Equipment Mobile CNC flange milling system
Applications Tower sections
Expected lifetime Similar to original
ISO 9001HIGH PRECISIONOEM TOLERANCESONSITE MACHINING
Reliable Bolt Connections Achieving flange flatness ensures even bolt preload and reduces the risk of fatigue, loosening, and premature failures throughout the turbine's service life.
Sub-Millimetre Precision Controlled CNC machining restores post-weld flange geometry to tight tolerances, ensuring accurate fit-up and repeatable manufacturing quality.
Repeatable Manufacturing Quality Fully CNC-controlled machining replaces manual correction methods with a predictable and repeatable production process.
Built For Offshore Scale Goliath machines monopile and transition piece flanges up to 12 metres in diameter, supporting the increasing size and complexity of offshore wind structures.
How It Works
Our Process
01
Quotation Request
We offer follow-up meetings with the customer. CNC Onsite’s follow-up program is part of our high quality standards.
02
Planning
We plan the technical part of the project, which includes preparation and programming of Goliath, the precision machine that will perform the milling. We plan staff availability and timing, including flexibility to accommodate potential changes to the schedule.
03
Implementation
Our technicians will conduct the precision milling of the flanges at the customer’s factory. Alternatively, CNC Onsite will train the customer’s own technicians for the operation of the machine. The team will use the Goliath machine to mill the flange faces, leaving them flat to within one millimeter.
04
Handover
After machining measurements are made, a measurement report is issued to the customer. Alternatively, the customer or a customer-contracted third party conduct the measurements. Once the measurement are complete, the customer signs off the work.
05
Follow-up
We offer follow-up meetings with the customer. CNC Onsite’s follow-up program is part of our high quality standards.
“We constantly develop our manufacturing to ensure we can deliver the right products with the right tolerances that the industry requests. With larger flanges, integrating Goliath into our manufacturing process will allow us to continue to do just that. We are proud to support the development of the industry and, by securing the tolerances, we contribute to securing the integrity of these large structures and thereby the production of green power for many years.”
Talk to our team Get Expert Advice
Get Expert Advice
On Your Project.
Send us your damage report or turbine type and we will respond within one working day with an assessment and indicative quote.
