In certain extreme applications, a part made of individual segments may meet your critical performance requirements better than a single-piece unit.
Segmented seals ride directly along the shaft and are primarily used in low-pressure applications.
These seals contain a series of segmented carbon rings which contact the shaft or rotor. Segments inside the seal housing are kept in the proper location by anti-rotation keys or pins. A secondary seal is formed by the axial spring loading of the seal rings against the internal surface of the housing face. During movement, a continuous seal is always in contact with either the primary or secondary sealing surfaces.
Really two pieces in one, Qualiseal Controlled Gap/Bushing seals are the best solution when pressure is an issue.
Controlled gap or bushing seals are comprised of a carbon insert that is shrink-fitted into a separate retaining band. This floating circumferential ring assembly grows at a rate similar to that of the shaft when exposed to elevated temperatures.
Under normal operating conditions, the pressure on the airside is higher than the pressure on the oil side. This creates some air leakage through the controlled gap between the carbon ring and shaft. The differential air pressure, along with the spring load, provide the closing force necessary to maintain contact between the carbon and housing secondary sealing face. Meanwhile, the shaft turns freely within the carbon ring.
The seal design also features a unique stabilizer ring with fins which minimize stress on the carbon ring, thereby maintaining the roundness of the circumferential ring assembly. The dimensional tolerance of the critical inside diameter of the bushing ring is tightly controlled to minimize leakage variations.
Qualiseal Hydrodynamic Lift Off Seals are non-contacting film-riding seals that have been successfully used in industrial pump and compressor applications for decades and are now increasingly finding their way into demanding aerospace applications where the hydrodynamic features can be even more beneficial. We design hydrodynamic features into the face of the mating ring. As the mating ring rotates, these features force air into a converging gap in the sealing surface, causing a pressure increase between the primary sealing elements. Once the pressure becomes great enough, the faces separate and the part operates in a hydrodynamic or non-contacting mode. The hydrodynamic features use air from the inside diameter to generate lift. A static sealing dam prevents leakage when the part is not rotating. In many aerospace applications, the rapid thermal transition, constantly changing pressures and high altitude conditions demand solutions where seal flatness must be maintained reliably over the long haul. Using a non-contacting seal enables the face seal and mating ring to operate virtually leak-free and experience almost no wear.
Pushing the outer limits of speed and vibration with your critical application? We have two words for you. No problem. Qualiseal Technology contacting face seals are known for versatility and exceptional performance across a wide range of demanding aircraft and industrial applications. They are designed for optimum performance where high speed and vibration are the norm. As the stationary portion of a seal assembly, contacting face seals are generally paired with a rotating mating ring, bearing or shaft. The seal face in the stationary portion provides the low-friction wear element that rides on the harder wear-resistant mating surface. The seal face and mating surfaces are typically lapped flat to within 0.0000348 inches (3 helium light bands), which provides virtually leak-tight sealing between the sealing interface. With the aid of Finite Element Analysis (FEA), mechanical face seal design at Qualiseal Technology is optimized to meet or exceed the most extreme unit operating conditions, with long life and reliable performance.
| Technetics Group | Technetics Group | Technetics Group | Technetics Group | |
|---|---|---|---|---|
| Product Category | Mechanical Seals | Mechanical Seals | Mechanical Seals | Mechanical Seals |
| Product Number | QUALISEAL | QUALISEAL | QUALISEAL | QUALISEAL |
| Product Name | Segmented Circumferential Seals | Controlled Gap/Bushing Circumferential Seals | Hydrodynamic Lift Off Mechanical Seals | Contacting Face Seals |
| Spring Element | Single Spring | Single Spring | Single Spring | |
| Seal Application | Gas Seal (Spiral Groove Seal); Aerospace, Industrial | Aerospace, Industrial | Pump; Cryogenic Seal; Aerospace | Pump; Aerospace, Industrial, Flow Control |
| Features | Balanced | Balanced; Unbalanced | Balanced; Unbalanced | |
| Rubbing Speed | 40000 ft/min (20320 cm/sec) | 50000 ft/min (25400 cm/sec) | 50000 ft/min (25400 cm/sec) | 50000 ft/min (25400 cm/sec) |
| Operating Pressure | 100 psi (70.38 m H2O) | 1.49 to 99.93 psi (1.05 to 70.33 m H2O) | 2 psi (1.41 m H2O) |
