The newly developed Turcon Variseal SA from Trelleborg Sealing Solutions provides a PTFE based sealing product suitable for the solid glands preferred by aerospace engineers. This seal offers easy installation combined with high temperature operation, chemical resistance and low friction, making it suitable for high frequency applications such as fight control.
To house seals, aerospace engineers favour use of a solid gland, a simple groove cut into component hardware, to simplify installation. Slipper seals, which are compact in design, can fit into these without a problem. However, the spring energised Turcon Variseal is an alternative sealing option that has a number of advantages in aircraft applications. Its jacket of Turcon, the Trelleborg Sealing Solutions proprietary PTFE based material, is capable of operating in extremes of temperature and is resistant to aggressive aerospace fluids such as synthetic hydrocarbon, petroleum base, phosphate ester and all types of aviation jet fuels. It also has a very low coefficient of friction, which optimises sealing load, making it ideal for the high frequency cycling of primary flight controls.
During installation into a solid gland, seals need to be compressed substantially. Due to the lip configuration of the Turcon Variseal, the spring energiser within it tends to flare its jacket outwards. This makes installation very difficult without a split gland, especially in smaller diameter housings. The problem is tackled with Turcon Variseal SA, which is specially designed for closed glands. Its Slantcoil spring is not susceptible to compression set and can accommodate more deformation than other springs during installation. While providing all the inherent capabilities of a Turcon Variseal, the Turcon Variseal SA is suited for fitment in even the smallest diameter Mil-G-5514F glands.
“The development of Turcon Variseal SA represents a significant product advancement, bringing real benefits to our customers,” says Brian Bowen, chief product engineer responsible for the new product at Trelleborg Sealing Solutions Bridgwater. “It expands the use of Turcon Variseal in aerospace applications and as it can directly replace slipper seals or O-Rings in standard grooves, it can give improved performance in existing housings.”