Implications of PFAS Restrictions on Sealing Technology

Typically, a standard hydraulic cylinder, the lock cylinder locks the rotor and blades in position for maintenance operations. Seals commonly used are:

- Zurcon® U-Cup RU9 rod seal

- Zurcon® Wynseal piston seal

- Orkot® Slydring® prevents metal to metal contact in the cylinder

- Zurcon® Scraper DA22 protects the cylinder by preventing ingress of dirt and debris

Pitch control systems consist of a series of cylinders and control valves, which pitch the rotor to ensure the optimal angle against the wind. These systems can operate as electrical or hydraulic systems. Electric systems require a stable power grid and battery backup.

In hydraulic pitch control systems, quality, reliability and service life are critical. Pitch cylinders operate at a high frequency using short strokes.  A typical sealing solution consists of:

- Zurcon® U-Cup RU9 rod seal

- Zurcon® Wynseal piston seal

- Orkot® Slydring® prevents metal to metal contact in the cylinder

- Zurcon® Scraper DA22 protects the cylinder by preventing ingress of dirt and debris

Hydraulic brakes perform different functions on wind turbines. The main brake, often featuring a hydraulic disc brake, assists in bring the rotors to a standstill. The yaw or azimuth brake keeps the nacelle positioned against the wind. These hydraulic powered brakes are equipped with plunger cylinders to hold the tower in position.

Accumulators, typically piston accumulators, are an important safety feature in wind turbines. They help turn the blade away from the wind in an emergency and also maintain pressure in hydraulic systems when the pump is off, reducing power consumption.

Sealing system for typical accumulator:

- Turcite® Slydring®

- Turcon® AQ-Seal®

- Turcon® Stepseal® 2A

Blade bearings sit between the hub and the three wing blades. They are exposed to the environment and offshore and desert climates can cause premature seal failure. Our experts support with seal specification to match the operating environment. Typically used seals include:

- V-Ring® rotary shaft seals

- Large diameter X-Seal to accommodate extreme conditions

- Custom molded X or double V designs provide increased flexibility against eccentricity

At the sandwich mount, between the top of the tower and the turbine, anti-fretting pads facilitate smooth turning of the rotors. Orkot® pads prevent metal-to-metal contact and reduce wear and damage to the surfaces.