BD – buffer seal
The BD rod seal is the result of a further development with a secondary sealing lip and a highly extrusion resistant back-up ring. Due to the secondary lip, additional lubricant is retained in the sealing gap. This greatly prevents dry-run and wear, thus increasing the seals service life. Additionally, this second sealing lip may even act as a substitute for a costly tandem arrangement when, under certain conditions, satisfactory sealing performance can only be achieved by two seals placed one behind the other in separate installation grooves.
These seals may be used for all applications where the physical properties of normal or fabric reinforced elastomers are insufficient.
• Exceptionally high static and dynamic sealing performance.
• Enhanced sealing performance in nonpressurized conditions.
• Penetration of air into the system is largely prevented.
• Robust seal profile for harshest operating conditions.
• Extreme wear resistance.
• Easier installation.
• Insensitive to extreme pressure peaks.
• Improved lubrication due to pressure medium deposit in the dynamic contact area.
• Extremely high extrusion resistance.
• Excellent media resistance in case of suitable compound selection.
• Suitable compounds available for special requirements of the chemical process industry.
• Suitable compounds available for special requirements of the food processing industry.
• Dimensions according to ISO 5597.
• Installation in closed and undercut housings.
• Low compression set.
• Additional sizes of machined products available on short notice.
Range of application
Mainly for the sealing of piston rods and plungers on heavy duty applications in mobile and stationary hydraulics.
| Operating pressure | ≤ 500 bar |
| Pressure peaks | ≤ 1000 bar |
| Operating temperature | -35 °C to +110 °C |
| Sliding speed | ≤ 0.5 m/s |
| Media | Hydraulic oils based on mineral oil |
Installation
The seals should have an axial clearance (see columns H and L). To avoid damage at the sealing lips, the seals should not be pulled over sharp edges during installation.
Normally these seals may be snapped into closed grooves. Where access is restricted special assembly tools may be required. Proposals for the design of such tools will be provided on request. For gap sizes see chapter “Maximum Gap Allowance”.
| d | D | H | L | d1 |
| 40 | 55 | 11.4 | 12.5 | 40.5 |
| 50 | 65 | 11.4 | 12.5 | 50.5 |
| 56 | 71 | 11.4 | 12.5 | 56.5 |
| 60 | 75 | 11.4 | 12.5 | 60.5 |
| 63 | 78 | 11.4 | 12.5 | 63.5 |
| 65 | 80 | 11.4 | 12.5 | 65.5 |
| 70 | 85 | 11.4 | 12.5 | 70.5 |
| 75 | 90 | 11.4 | 12.5 | 75.5 |
| 80 | 95 | 11.4 | 12.5 | 80.5 |
| 85 | 100 | 11.4 | 12.5 | 85.5 |
| 85 | 100 | 12 | 13 | 85.5 |
| 90 | 105 | 11.4 | 12.5 | 90.5 |
| 95 | 110 | 12 | 13 | 95.5 |
| 100 | 115 | 12 | 13 | 100.5 |
| 100 | 120 | 13.5 | 15 | 100.6 |
| 100 | 120 | 14.5 | 16 | 100.6 |
| 110 | 130 | 14.5 | 16 | 110.6 |
| 120 | 140 | 14.5 | 16 | 120.6 |
| 125 | 145 | 14.5 | 16 | 125.6 |
| 130 | 150 | 14.5 | 16 | 130.6 |
| 140 | 160 | 14.5 | 16 | 140.6 |
| 150 | 170 | 14.5 | 16 | 150.6 |
| 160 | 180 | 14.5 | 16 | 160.6 |
| 170 | 190 | 14.5 | 16 | 170.6 |
| 180 | 205 | 18.2 | 20 | 180.8 |
| 190 | 215 | 18.2 | 20 | 190.8 |
| 200 | 230 | 22.7 | 25 | 200.8 |
| 210 | 240 | 22.7 | 25 | 210.8 |
| 220 | 250 | 22.7 | 25 | 220.8 |
| 230 | 260 | 22.7 | 25 | 230.8 |
| 240 | 270 | 22.7 | 25 | 240.8 |