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 |