

The dimensions of the 20BU seal are shown above. Seals BU in other sizes are shown in the configurator and catalogue card, available at the top of the page.
General characteristics
Single seal, cartridge design, independent from the direction of rotation, multi-spring. The seal acc. to EN ISO 21049 (API 682): type A, category 2 or 3, arrangement 1, configuration 1CW-FL (with a floating carbon throttle bushing).
Range of sizes available
- Shaft diameter: d = 20 ... 110 mm
Operating parameters
- Pressure: < 4.2 MPa
- Temperature: < 180 °C
- Velocity: < 20 m/s
Applications
The BU is a single mechanical seal used for media contaminated with particulate solids, especially, e.g., crude oil and polluted hydrocarbons.
BU seal requires auxiliary installations acc. to API 682 (EN ISO 21049), Plan: 11/61, 11/62, 12/61, 12/62, 13/61, 13/62.
Available options
Materials
- Rotating ring: Q, U
- Stationary ring : A, B, Q, U
- Secondary flexible seals: E, K, P, V
- Spring (springs): M
- Other metal parts: G, M