RADIAL TURBINE SEAL
Radial type seals are used in hydroelectric turbines, pump-turbines and large pumps.
The primary purpose of a mechanical radial shaft seal is to maintain a near watertight seal between the turbine shaft and the head cover.
Depending on the pressure under the seal, two or more carbon segmented sealing rings are required. This seal is reliable, relatively simple to install and easy to operate and maintain
All of our radial type shaft seals are fully split or non-split and specifically designed for hydropower generating turbines. The seal can be custom designed and adapted to the existing turbine configuration and specification in order to meet the operating requirements.
For small shaft diameters, these seals can be designed with anti-rotation pins positioned in the cover and in the lower chamber ring to maintain a low seal profile. For easier installation we recommend the use of an intermediate ring with the stop pins located between the two sealing rings in order to facilitate installation. If required, an inflatable seal can be supplied to allow maintenance without dewatering the turbine.
A basic turbine seal consists of a base ring and a cover ring forming the cavity that houses the sealing rings. The cover ring is secured to the base ring that, in turn, bridges the gap between the turbine shaft and the head cover and also serves to house the inflatable seal (if required).
The cover ring can also be designed to act as a reservoir to accumulate water on top of the seal to prevent a dry running condition of the top sealing ring in the event that the turbine is operating under vacuum conditions.
Each sealing ring assembly consists of overlapped and interchangeable carbon segments, compression springs and garter springs. The carbon segments are positioned around the shaft to perform the sealing function.
|MODEL||Type F200, F201, F210, F211||Type F310, F311|
|Max. Turbine operating pressure||140 kPa (20psi)||280 kPa (40 psi)|
|Max. Recommended barrier water pressure||20-35 kPa (3-5 psi) above turbine pressure||20-35 kPa (3-5 psi) above turbine pressure|
|Recommended water filtration||25 microns||25 microns|
|Radial shaft dislocation:||± 1.5 mm (0.06")||-± 1.5 mm (0.06")|
|Axial shaft dislocation||No restrictions||No restrictions|
|Shaft /sleeve finish||32 RMS||32 RMS|