BECA 745 - 747
Description
The BECA 745 - 747 roto seals are single or double acting rod rotary seals composed of a filled PTFE grooved friction ring and two pre-tightened rubber O'Rings.
Advantages
Low friction coefficient; no stick-slip effect on start up
Excellent abrasion and extrusion resistance
The grooves provide an integrated lubrication system
Excellent dimensional stability
Technical data
| Temperature | -30°C/+200°C |
|---|---|
| Pressure | 30 MPa |
| Speed | 2 m/s |
| Medias | Mineral hydraulic oils |
Applications
Rotary distributors
Handlers
Hydraulic motors
Materials
Friction ring
Bronze-filled PTFE
Carbon-filled PTFE
Virgin PTFE
O'Rings
NBR 70 Shore A
FKM 70 Shore A
Dimensions
Installation dimensions
Installation dimensions
| Rod diameter Ød1 f8/h9 |
Groove diameter ØD1 H9 |
Groove width | O'Ring cross-section |
|||||
|---|---|---|---|---|---|---|---|---|
| BECA 745 Standard series |
BECA 747 Heavy-duty series |
s (m/s) < 0.2 p (MPa) < 2.5 |
0.2 < v (m/s) < 0.5 2.5 < p (MPa) < 5.0 |
0.5 < v (m/s) < 1.0 5.0 < p (MPa) < 25.0 |
1.0 < v (m/s) < 2.0 25.0 < p (MPa) < 40.0 |
2.0 < v (m/s) < 5.0 40.0 < p (MPa) < 50.0 |
L1 0/+0.20 | Ød2 |
| 6.0 - 18.9 | --- | d1 + 4.20 | d1 + 4.40 | d1 + 4.50 | d1 + 4.60 | d1 + 4.70 | 4.30 | 1.78 |
| 19.0 - 37.9 | 6.0 - 18.9 | d1 + 6.20 | d1 + 6.40 | d1 + 6.60 | d1 + 6.80 | d1 + 6.90 | 6.30 | 2.62 |
| 38.0 - 199.9 | 19.0 - 37.9 | d1 + 8.40 | d1 + 8.60 | d1 + 8.90 | d1 + 9.10 | d1 + 9.30 | 8.50 | 3.53 |
| 200.0 - 255.9 | 38.0 - 199.9 | d1 + 12.70 | d1 + 13.00 | d1 + 13.40 | d1 + 13.80 | d1 + 14.00 | 12.90 | 5.33 |
| 256.0 - 649.9 | 200.0 - 255.9 | d1 + 16.60 | d1 + 17.00 | d1 + 17.50 | d1 + 18.00 | d1 + 18.30 | 16.90 | 6.99 |
For special applications > 20 MPa, we recommend using an H8/f8 tolerance (groove/rod) or selecting other more suitable materials. Please contact our experts.
Materials
| Friction ring | O'Rings | Contact surface area | ||||||
|---|---|---|---|---|---|---|---|---|
| Standard code | ISO code | Material | Colour | Characteristics | Code | Type of material | Service temperature | |
| DP | P | Virgin PTFE | White | Resistance to chemical products Sealing water Dielectric Non-stick Low friction coefficient Food & Beverage |
K6 | NBR 70 Shore A | -30°C/+100°C | Steel Stainless steel Chrome steel Aluminium Bronze Cast iron Treated surface |
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| C6 | EPDM 70 Shore A | -45°C/+150°C | ||||||
| F6 | VMQ 70 Shore A |
-60°C/+200°C | ||||||
| DC | C | PTFE +25% Carbon |
Grey |
Improvement
Good resistance to chemical products Efficient as part of dynamic |
K6 | NBR 70 Shore A | -30°C/+100°C | |
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| C6 | EPDM 70 Shore A | -45°C/+150°C | ||||||
| CG | C | PTFE + 23% Carbon + 2% Graphite |
Black | K6 | NBR 70 Shore A | -30°C/+100°C | ||
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| C6 | EPDM 70 Shore A | -45°C/+150°C | ||||||
| DV | V | PTFE + 25 % Glass |
Blue | Improvement
corrected with the addition of MOS2 Chemical and dielectric properties preserved Well suited to applications with rotating and simultaneous alternating movements |
K6 | NBR 70 Shore A | -30°C/+100°C | Steel Chrome steel Cast iron |
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| VM | M | PTFE + 15 % Glass + 5% MoS2 |
Grey | K6 | NBR 70 Shore A | -30°C/+100°C | ||
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| DG | G | PTFE + 15% Graphite |
Black | Improvement
Self-lubricating Thermal and electrical conductivity Low permeability Good friction coefficient Anti-static Efficient as part of dynamic dynamic applications with self-lubrication |
K6 | NBR 70 Shore A | -30°C/+100°C | Steel Stainless steel Chrome steel Aluminium Bronze Cast iron Treated surface |
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
| C6 | EPDM 70 Shore A | -45°C/+150°C | ||||||
| DB | B | PTFE + 60% Bronze |
Dark brown | Improvement
Electrical and thermal conductivity Does not alter metal parts Reduced resistance to certain chemical products Used for dynamic seals with a strong compression and low level of wear |
K6 | NBR 70 Shore A | -30°C/+100°C | Steel Chrome steel Cast iron |
| G6 | FKM 70 Shore A | -20°C/+200°C | ||||||
Other grades of materials are available depending on your specificities.
Technical data
Extrusion gaps
| Radial section S |
Radial extrusion gap F/2 |
||
|---|---|---|---|
| 10 MPa | 20 MPa | 30 MPa | |
| 2.45 | 0.15 | 0.10 | 0.05 |
| 3.75 | 0.20 | 0.15 | 0.10 |
| 5.50 | 0.25 | 0.20 | 0.15 |
| 7.75 | 0.30 | 0.25 | 0.20 |
| 10.50 | 0.30 | 0.25 | 0.20 |
| 14.00 | 0.45 | 0.30 | 0.25 |
Surface roughness
| Roughness | Dynamic surface area | Static surface area |
|---|---|---|
| Ra | 0.05 - 0.2 µm | ≤ 1.6 µm |
| Rz | 0.4 - 1.6 µm | ≤ 10.0 µm |
| Rmax | 0.63 - 2.5 µm | ≤ 16.0 µm |
Chamfers and radius
| Radial section S |
Radius R1 |
Radius R2 |
Chamfer C |
|---|---|---|---|
| 2.45 | 0.20 | 0.40 | 2.00 |
| 3.75 | 0.20 | 0.60 | 2.50 |
| 5.50 | 0.20 | 1.00 | 3.50 |
| 7.75 | 0.20 | 1.30 | 5.00 |
| 10.50 | 0.20 | 1.80 | 6.50 |
| 14.00 | 0.20 | 2.50 | 7.50 |
Only on request