What are External Pressure Face Seals
External Pressure Face Seals are devices that seal the space between mechanical equipment. It is designed to prevent external pressure or media from entering between the two faces. This type of seal is used to seal corrosive media or gases and vacuum conditions. The additional load of the coil spring provides an airtight seal even under fluctuating temperature cycles.
Special Characteristics
- External pressure: Unlike other sealing devices, external pressure surface sealing achieves the sealing effect through external pressure. External pressure brings the sealing surfaces together to form a sealing layer that resists leakage of liquid or gas.
- Double-sided seals: External pressure face seals usually consist of two flat or curved sealing elements, which means they can achieve double-sided sealing. Even if one sealing surface has problems or is damaged, the other sealing surface can still maintain the sealing effect.
- Axial offset and vibration compensation: The external pressure face seal has good adaptability and can accommodate axial offset and vibration. In high-speed rotating equipment or applications where axial movement is present, an external pressure face seal can maintain a stable seal and reduce the risk of leakage.
- High-temperature applications: The external pressure surface seal has high-temperature resistance and can maintain the sealing effect in high-temperature environments. This makes them excellent in equipment that requires sealing under high-temperature conditions, such as high-temperature pumps, oil refining equipment, etc.
Advantages compared to other seals
■ High sealing efficiency: The external pressure surface seal uses external pressure to tightly fit the sealing surfaces together to form an efficient seal. In comparison, other sealing devices such as O-rings or mechanical seals may require more friction or pressure to achieve a sealing effect.
■ Good adaptability: The external pressure face seals can adapt to large axial deflection and vibration, keeping the sealing effect stable. This makes them more reliable in high-speed rotating equipment or applications where axial movement is present.
■ Higher pressure resistance: The external pressure surface seal can withstand higher pressure and is suitable for high-pressure systems. In contrast, some other sealing devices may be susceptible to leakage or damage under high pressure.
It should be noted that this seal has its specific applications and limitations and needs to be customized. Please send us the drawing if you need it.
Applicable working conditions
1. High-pressure environment: The external pressure surface seal can withstand higher pressure and is suitable for high-pressure systems. They can effectively prevent liquid or gas leakage and ensure the safe operation of equipment. This makes them widely used in high-voltage equipment in petroleum, chemical, energy, and other industries.
2. High-speed rotation: External pressure surface sealing is suitable for high-speed rotating equipment, such as pumps, compressors, turbines, etc. The rotating parts of this equipment need to have reliable seals to prevent leakage and reduce energy loss. The external pressure face seals can maintain a stable sealing effect under high-speed operation through the design of external pressure and double-sided sealing.
3. High-temperature environment: The external pressure surface seal has high-temperature resistance and is suitable for high-temperature working conditions. They maintain a seal at high temperatures and resist leakage of liquids or gases. Therefore, an external pressure face seal is widely used in high-temperature equipment in petrochemical, energy, and manufacturing fields.
4. Axial deflection and vibration: The external pressure surface seal has good adaptability and can accommodate axial deflection and vibration. In rotating equipment or applications where axial movement is present, the external pressure face seal maintains a stable seal and reduces the risk of leakage. This makes them widely used in turbine machinery, mixing equipment, and other applications that require motion sealing.
Product Parameters
| PTFE | ||||
| Property | Unit | Test Method | Test Parameter | Typical Value |
| Hardness | Shore D | ASTM D2240 | (Shore D - 15 sec) | 60 |
| Specific gravity | g/cm3 | ASTM D792 | 2.15 | |
| Tensile strength | MPa | ASTM D638 | Microtensile specimen of ASTM D1708, speed of testing 0.8mm/s |
28 |
| Ultimate elongation | % | ASTM D638 | Microtensile specimen of ASTM D1708, speed of testing 0.8mm/s |
300 |
| Compressive strength 1% deformation |
MPa | ASTM D695 | 4.56 | |
| Modulus of Elasticity | MPa | ASTM D638 | 280 | |
Operating Range
| Material | Operating Pressure up to | Maximum Pressure up to | Temperature | Surface Speed up to | Fluid, Media Compatability |
| PTFE, FKM, etc. | 5,000psi (350bar) vacuum | 10,000psi (700bar) | -328°F to 500°F (-200°C to 260°C) | 0.3ft/s (0.1m/s) intermittent |
vacuum service, aggressive chemicals, cryogenic service, FDA (both contact and non-contact), fugitive emissions, as well as control fluids, hydraulic fluids, and dry running in a wide range of gases. |
| *IMPORTANT NOTE: The above maximum values depend on the extrusion gap, gap, sealing material, media, temperature, pressure, surface speed, dynamic operating surface finish, and working environment. Seals cannot operate at their higher ratings at the same time. For pressures above 3.000psi (210 bar) or temperatures above 200°F (95°C), please contact our technicians for seal material and hardware specifications. | |||||
Hot Tags: external pressure face seals, China external pressure face seals manufacturers, suppliers, factory, Automobile ACM Rubber Seals, Aviation AEM Rubber Seals, Door and Boot Wiring Sheath Grommet, Food Grade Gummiformteile, Missile Launcher VITON Sealing O Rings, Medical LSR Seals
