KPMBOLT super nuts adopt full-process non-destructive testing, suitable for wind towers, main frames and blade flanges. Resistant to alternating wind load and long-term loosening, it eliminates hidden dangers of fastener relaxation at high altitude.
Wind power is a core pillar of clean energy and new energy layout. Wind turbines are often located in mountains, plains and coastal areas, enduring strong wind load, turbulence, temperature difference and continuous vibration. Key connections such as tower flanges, main frames, cabin bases, blade flanges and pitch bearings bear irregular wind impact and alternating load, which easily cause fastener loosening, preload attenuation and flange displacement. Wind turbine equipment is installed dozens of meters above the ground. Once ordinary nuts loosen or fail, it will lead to abnormal vibration, unbalanced blade operation, flange cracking and even component falling, causing serious safety accidents and high maintenance costs. Traditional ordinary nuts and spring washers have poor resistance to alternating load. They relax easily after long-term wind vibration and require frequent high-altitude inspection and re-tightening, which brings high operation risk, high labor cost and huge shutdown loss. It can no longer meet the demand of long-term safe operation of large wind farms. With century-level heavy-duty fastening technology, KPMBOLT super nut adopts multi-jackbolt axial pre-tightening structure instead of traditional friction anti-loosening mode. Strict full-process quality control is implemented from material forging, heat treatment to ultrasonic and magnetic particle non-destructive testing.
Specially developed for high-altitude, alternating wind load and large temperature difference in wind power industry, it becomes the optimal long-term fastening solution for wind tower and main flange. KPMBOLT super nut consists of nut body, jackbolts and high-strength thrust washers, with independent quality inspection and traceability files. The nut body is forged from high-grade alloy steel, with strict material certification and spectral chemical inspection. After quenching and tempering, hardness is controlled at HRC 30–36 with piece-by-piece inspection. 100% ultrasonic testing eliminates internal defects to ensure structural stability outdoors. The high-strength jackbolts are made of ultra-high strength alloy steel with hardness HRC 48–54 and yield strength over 1500MPa.
Full hardness test, mechanical property test and 100% magnetic particle inspection avoid surface micro-cracks and fatigue fracture risk at high altitude. The matched thrust washer is precisely ground after heat treatment with hardness HRC 40–44, dispersing flange stress effectively and protecting sealing surface from deformation. Adopting pure axial preload design, no shear stress or extra bending moment is generated during installation. Evenly distributed preload can resist alternating wind load and temperature change without preload attenuation. Widely used in wind tower flanges, cabin bases, blade root flanges, pitch bearings and yaw brake discs. Complete specifications M30–M150 can directly replace original nuts without equipment modification. Installation only needs standard torque wrench, suitable for high-altitude narrow space and field construction, greatly reducing operation risk and construction time. After long-term operation, KPMBOLT super nut features wind vibration resistance, good weather resistance and stable locking performance. Maintenance-free cycle matches wind turbine overhaul period without annual high-altitude re-tightening. Practical wind farm data shows that fastener loosening failure is reduced by more than 90%, whole-machine vibration is obviously improved, and flange displacement and abnormal noise are greatly eliminated. It saves a lot of maintenance labor, spare parts cost and power generation loss caused by shutdown. Complete material certificates, heat treatment records and NDT reports are available with full traceability, complying with wind power mechanical design and high-altitude fastener safety standards. With the large-scale development of onshore and offshore wind power and intelligent operation, wind turbines put forward higher requirements on fastener fatigue resistance and long-term maintenance-free performance. KPMBOLT super nut, with German precision manufacturing and full-process testing, provides safe, stable and economical heavy-duty fastening for wind towers, main frames and blade flanges, supporting the high-quality and steady development of new energy wind power industry.
References:
- Wind Turbine Fastener Design Specification;
- KPMBOLT MPP Inspection Plan;
- Research on Anti-fatigue Fastening Technology for Wind Power Flange.