Burks 21942-1 Mechanical Seal
The Burks 21942-1 seals the shaft where it leaves the pump casing. It is a mechanical face seal - a spring-loaded rotating face running against a stationary seat, self-adjusting as the faces wear.
A mechanical seal is a wear part with a finite life. The carbon face is sacrificial and slowly gives itself up against the harder seat, and the spring takes up the wear until it runs out of travel. What ends most seals early, though, is a dry start, a starved suction line, or grit carried through the faces. The warning is usually a drip that appears after shutdown and then becomes constant.
Handle the faces as though they were optical parts, because that is effectively what they are. Keep them clean, do not touch the lapped surfaces, and never lever the seal into place. so match the material as carefully as the size.
Key Features
- Genuine Burks mechanical shaft seal assembly
- Built to the original Burks shaft dimension
- Original Burks material specification
- Direct replacement for the original Burks seal
- Spring loaded and self-adjusting as the faces wear
- Supplied complete - rotating face, seat and elastomers
Applications
- Burks pump rebuilds and overhauls
- Curing a persistent drip from behind the pump casing
- Recovery after a dry run or a lost prime
- Replacing seal faces scored by grit or abrasives
- Planned maintenance on duty and standby pumps
- Industrial, marine and dockside pump installations
Specifications
- Brand: Burks
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 21942-1
- Part Type: Mechanical shaft seal
- Condition: New
Frequently Asked Questions
Q: A few drops appear when the pump first starts. Is that normal?
A very light initial weep while the faces bed in can settle within an hour or so of running. A steady drip, or anything that continues beyond that, means the faces are not seating and the seal needs to come back out.
Q: How do I know the seal is what is leaking?
A shaft seal leak shows up as liquid finding its way out around the shaft behind the casing, often worst just after shutdown. A joint gasket leaks along the split line between castings and does not change with shaft rotation.
Q: What ruins a new seal fastest?
Running the pump dry, even briefly. The faces depend on a thin liquid film for both lubrication and cooling, and seconds without it can heat-check the carbon. Close behind that are grit in the liquid and an elastomer that is wrong for the chemistry.
Q: Can I touch the lapped faces while fitting it?
Keep your fingers off them. The faces are polished to within a fraction of a light band and skin oil or a single hard particle left on them will hold them apart. Wipe with a clean lint-free cloth, use the recommended lubricant, and press home with even pressure.
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 mechanical seal before you order.
CLRMarine
