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Stein Seal provides design, testing, and manufacturing services for seals and precision components, including carbon bushing seals for high-pressure gas and liquid applications. Fixed, solid carbon, floating, solid metal, segmented, and carbon insert and metal banded bushings are available.

Stein’s bushing seals are perfect for high-pressure gas and liquid applications. Each bushing seal is custom designed to fit the application and can be combined with our other seals to create sealing systems that meet the most stringent operating requirements.

The bushing seal is a clearance seal consisting of a close-fitting stationary sleeve within which the shaft rotates. The leakage is controlled from the high-pressure side of the bushing to the low-pressure side by the restricted clearance between the shaft and the bushing bore. Bushing seals can be designed in either a fixed- or floating-sleeve configuration, depending upon the operating clearance requirements, shaft movement, and vibration. The fixed bushing seal consists of a long sleeve affixed to the machine housing and offers possibilities for a relatively inexpensive assembly. Being fixed, however, it behaves like a redundant bearing when rubbing occurs and requires large clearances. A floating bushing can move in a radial direction relative to the shaft and machine housing. The floating characteristic permits them to move relatively freely with shaft movement and deflections, providing the advantage of a closer annular clearance and avoiding severe shaft rub.

Another floating bushing type used in such machinery as steam turbines is a segmented carbon ring held in segmented metal retainers and bound by a garter spring. It provides ease of installation and maintenance of the shaft.

Typical applications include aircraft engine main shaft seals, compressors, pumps, and high-speed processing equipment. Configurations include either a floating or fixed design, depending on the tolerances of the specific seal application.

Key Bushing Seal Features:

Floating bushings move radially but are captured axially in the housing with spring loading to better tolerate any shaft movement.

Available in a wide variety of materials suitable to each application: alloys, steels, 300/400 series stainless steel, Inconel, Hastelloy, ceramics, and carbon graphite

Types of Bushings:

  • Fixed Bushing
  • Solid carbon Bushing
  • Float Bushing
  • Solid metal Bushing
  • Segmented Bushing
  • Carbon insert and metal-banded Bushings

General Bushing Seals Performance Characteristics:

  • Shaft rotation speeds up to 152.4 meters per second (500 feet per second)
  • Temperature ranges up to 300° C (500° F)
  • Pressure ranges up to 20,000 KPa (3000 psi)
  • Diameter sizes range up to 40 cm (18 in.)
  • Bushings (Controlled Gap)
  • Metal Banded Carbon Graphite