PTFE Back-up Rings have no intended sealing function. Instead, as their name indicates, they are protective and supporting elements made from extrusion-resistant materials which generally have a rectangular cross section. They are installed in a groove together with an elastomeric sealing element preferably with a corresponding O—Ring in static applications. Due to the tight fit of the Back-up Ring in the housing, they prevent extrusion of the pressurised elastomeric sealing element into the sealing gap.
Advantages
- Use of O—Rings in high pressure applications
- Use of O—Ring materials with a low hardness
- Compensation of radial sealing gaps
- Use for internal and external sealing applications
- Reciprocating and rotating movements possible
- Compensation for large temperature fluctuations
- Static and dynamic applications
Back-up Ring types, uncut
Type BV
- Rectangular cross section
- Material PTFE
- Static and dynamic use
- Reciprocating and rotating movements possible
Type BB
- Concave cross section
- Materials: NBR, FKM
- The large contact surface protects the O—Ring against
deformation in case of high pulsating pressure
- Dimensional stability of the O—Ring improves the sealing
force and increases the service life
- Preferably for static use
- Reciprocating movements possible
Type BA
- Concave cross section
- Material: PTFE
- The large contact surface protects the O—Ring against
deformation in case of high pulsating pressure
- Dimensional stability of the O—Ring improves the sealing
force and increases the service life
- Static and dynamic use
- Reciprocating and rotating movements possible
Type BD
- Concave cross-section
- Material: PTFE
- Cut angle of 30° or 45°
- The large contact surface protects the O—Ring against
deformation in case of high pulsating pressure
- Dimensional stability of the O—Ring improves the sealing
force and increases the service life
- Static and dynamic use
- Reciprocating movements possible
- Preferred for installations in a closed groove where uncut
Back-up Rings are not suitable
Back-up Ring types, spiral
Type BP
- Rectangular cross section
- Material: PTFE
- Cut angle of 30° or 45°
- Consists as standard two spiral windings which are cut at
the ends at an angle
- Static and dynamic use
- For reciprocating movements only
- Preferred for installations in a closed groove where uncut
Back-up Ring are not suitable
- Compensation of large temperature changes and
tolerances without difficulties by a screw-like
elongation and contraction. Easy Installation in closed
grooves for external sealing applications
- The dimensions are different compared to standard Backup
Rings
Type BU
- Rectangular cross section
- Material: PTFE
- Static and dynamic use
- Reciprocating and rotating movements possible
Type BB
- Concave cross-section
- Materials: PTFE, NBR, FKM
- The large contact surface protects the O—Ring against
deformation in case of high pulsating pressure
- Dimensional stability of the O—Ring improves the sealing
force and increases the service life
- Static and dynamic use
- Reciprocating movements possible
Back-up Ring types, cut
Type BG
- Rectangular cross section
- Material: PTFE
- Cut angle of 30° or 45°
- Static and dynamic use
- Reciprocating and rotating movement possible
- Preferred for installations in closed grooves where uncut
Back-up Rings are not suitable
Type BC
- Concave cross-section
- Material: PTFE
- Cut angle of 30° or 45°
- The large contact surface protects the O—Ring against
deformation in case of high pulsating pressure
- Dimensional stability of the O—Ring improves the sealing
force and increases the service life
- Static and dynamic use
- Reciprocating movements possible
- Preferred for installations in a closed groove where uncut
Back-up Rings are not suitable
Type BP
- Rectangular cross section
- Material: PTFE
- Cut angle of 30° or 45°
- Consists as standard two spiral windings which are cut at
the ends at an angle
- Static and dynamic use
- For reciprocating movements only
- Preferred for installations in a closed groove where uncut
Back-up Rings are not suitable
- Compensation of large temperature changes and
tolerances without difficulties by a screw-like
elongation and contraction
External sealing (Bore)
Type BV
- Rectangular, uncut, PTFE
Type BH
- Rectangular, cut, PTFE
Type BD
- Concave, cut, PTFE
Type BP
- Spiral, PTFE
Type BB
- Concave, uncut, NBR + FKM
Type BA
- Concave, uncut, PTFE
Internal sealing (Rod)
Type BU
- Rectangular, uncut, PTFE
Type BG
- Rectangular, cut, PTFE
Type BC
- Concave, cut, PTFE
Type BP
- Spiral, PTFE
Type BB
-Concave, uncut, NBR + FKM + PTFE
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