The 491 Mechanical Seal is a reliable industrial sealing solution designed as a direct replacement for Chesterton 491. It is widely used in industrial pump systems, delivering stable and efficient sealing performance across a range of operating conditions.
Engineered with durable material combinations such as carbon, ceramic, silicon carbide, and stainless steel, the 491 offers excellent resistance to wear, corrosion, and moderate temperature and pressure conditions. Its robust construction ensures consistent operation and reduced maintenance requirements.
Ideal for industries seeking a cost-effective and dependable sealing solution, the 491 enhances equipment reliability while minimizing downtime in demanding industrial environments.
- Direct replacement for Chesterton 491
- High-performance mechanical seal for industrial pumps
- Supports multiple materials (Carbon / SIC / Ceramic / SS304)
- Durable design for long service life
- Reduced maintenance and downtime
- Reliable sealing performance
| Seal size d(mm) | d 3 | d 4 | d 6 | d 7 | l 1 | l 3 | MX |
| 16 | 29 | 31 | 23 | 27 | 35.0 | 5.0 | 4 |
| 18 | 32 | 34 | 27 | 33 | 37.5 | 7.5 | 4 |
| 20 | 34 | 36 | 29 | 35 | 37.5 | 7.5 | 4 |
| 22 | 36 | 38 | 31 | 37 | 37.5 | 7.5 | 4 |
| 24 | 38 | 40 | 33 | 39 | 37.5 | 7.5 | 4 |
| 25 | 39 | 41 | 34 | 40 | 37.5 | 7.5 | 4 |
| 28 | 42 | 44 | 37 | 43 | 42.5 | 7.5 | 5 |
| 30 | 44 | 46 | 39 | 45 | 42.5 | 7.5 | 5 |
| 32 | 46 | 48 | 42 | 48 | 42.5 | 7.5 | 5 |
| 33 | 47 | 49 | 42 | 48 | 42.5 | 7.5 | 5 |
| 35 | 49 | 51 | 44 | 50 | 42.5 | 7.5 | 5 |
| 38 | 54 | 58 | 49 | 56 | 44.0 | 9.0 | 5 |
| 40 | 56 | 60 | 51 | 58 | 44.0 | 9.0 | 5 |
| 43 | 59 | 63 | 54 | 61 | 44.0 | 9.0 | 5 |
| 45 | 61 | 65 | 56 | 63 | 44.0 | 9.0 | 5 |
| 48 | 64 | 68 | 59 | 66 | 44.0 | 9.0 | 5 |
| 50 | 66 | 70 | 62 | 70 | 44.5 | 9.5 | 5 |
| 53 | 69 | 73 | 65 | 73 | 46.0 | 11.0 | 5 |
| 55 | 71 | 75 | 67 | 75 | 46.0 | 11.0 | 5 |
| 60 | 80 | 85 | 72 | 80 | 46.0 | 11.0 | 5 |
| 65 | 85 | 90 | 77 | 85 | 46.0 | 11.0 | 5 |
| 68 | 88 | 93 | 81 | 90 | 46.3 | 11.3 | 5 |
| 70 | 90 | 95 | 83 | 92 | 46.3 | 11.3 | 5 |
| 75 | 99 | 104 | 88 | 97 | 59.3 | 11.3 | 6 |
| 80 | 104 | 109 | 95 | 105 | 60.0 | 12.0 | 6 |
| 85 | 109 | 114 | 100 | 110 | 60.0 | 12.0 | 6 |
| 90 | 114 | 119 | 105 | 115 | 62.0 | 14.0 | 6 |
| 100 | 124 | 129 | 115 | 125 | 62.0 | 14.0 | 6 |
| 110 | 134 | 139 | 125 | 135 | 62.0 | 14.0 | 6 |
- Industrial pump systems
- Water treatment and utilities
- Chemical processing plants
- Oil & gas applications
- General manufacturing industries
- Medium-duty industrial operations