Description
Non-contacting Gas Seal for Steam Turbines
Type 28ST combines proven rotating groove technology and high-temperature secondary seals to reduce steam leakage by nearly two orders of magnitude, as compared to traditional sealing devices, such as segmented carbon rings and labyrinths. This steam-lubricated, end-face cartridge seal reacts instantaneously and automatically to maintain a safe face gap despite sudden changes in operating conditions. A stable seal face gap, typically 0.0001" to 0.0002"/0.0025mm to 0.0051mm, is the result of specially designed rotating grooves, which pump steam radially inward into a nongrooved portion of the seal known as the "sealing dam."
Features
- Bearing oil steam contamination reduced.
- Standard designs fit most single-stage turbines.
- Reduced noise levels and hazards associated with leaking steam.
- Support equipment eliminated.
- Unidirectional and bidirectional capability.
Parameters
| Temperature Limits |
40°F to 500°F/-40°C to 260°C |
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| Pressure Limits |
400 psi(g)/27.6 bar(g) |
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| Speed Limits |
400fps/122m/s |
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| Size Limits |
6.5"/165mm |
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