Back Up Rings has no function for sealing by themselves. They are the most common anti-extrusion devices in dynamic sealing. Back Up Rings can be used to offset the reduced pressure rating effects of wear rings or to improve seal life at increased pressures.

BACK UP CONCAVES ARE AVAILABLE!

Type BV/BU
– Rectangular cross section
– Material PTFE
– Static and dynamic use
– Reciprocating and rotating movements possible
Type BB/BA
– 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 BH/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 BD/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
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