Burks 20997 Lip Seal 0.625 in ID by 1.50 in OD
This is the lip seal Burks supplies as part 20997, 0.625 in inside diameter by 1.50 in outside diameter. Unlike a mechanical face seal it seals radially against the shaft surface, which makes it simple, compact and entirely dependent on the condition of the shaft it runs on.
Lip seals fail in two ways. The lip hardens with heat and age until it no longer follows the shaft, and it wears a groove into the shaft that then defeats every subsequent seal fitted to the same position. The second problem is the expensive one, because the fix is a new shaft or a repair sleeve rather than a new seal.
Three dimensions define the part - shaft diameter, bore diameter and width - and this one is 0.625 in inside diameter by 1.50 in outside diameter. Getting any one of them wrong means either a seal that spins in its bore or a lip running with the wrong interference, and both leak.
Key Features
- Genuine Burks replacement lip seal
- 0.625 in inside diameter by 1.50 in outside diameter
- Spring energised lip for consistent shaft contact
- Keeps lubricant in and contamination out
- Direct replacement for the original Burks part
- Inexpensive item best renewed whenever access allows
Applications
- Burks pump service and overhaul
- Replacing a seal that has begun to weep at the shaft
- Protecting a bearing from contamination ingress
- Reassembly after a shaft or bearing replacement
- Planned maintenance spares kits
- Industrial, marine and dockside installations
Specifications
- Brand: Burks
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 20997
- Part Type: Lip seal
- Size: 0.625 in inside diameter by 1.50 in outside diameter
- Condition: New
Frequently Asked Questions
Q: Should the lip be lubricated before assembly?
Yes, lightly, with a lubricant compatible with the seal material and the system. A dry start on a lip seal can burn the lip within seconds, which is exactly the failure you are trying to prevent.
Q: How do I press it in without damaging it?
Use a driver that bears on the full outer case, not on the inner lip, and keep it square to the bore. A seal that goes in cocked will not seal, and levering it back out usually ruins it.
Q: Can I use a seal with the same dimensions from another supplier?
Dimensionally it will fit. What varies is the lip material, the spring and the case design, which decide the temperature range, the chemical compatibility and how long it lasts. Match the Burks specification where you can.
Q: How long should one last?
In clean conditions with a good shaft finish, years. Heat, abrasive contamination and shaft runout all shorten it sharply, and repeated early failures usually point at the shaft or the housing rather than the seal.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct lip seal before you order.
CLRMarine
