Burks 21157 Cast Iron Diffuser 5-1/2 in ID for 10WA6
This is the cast iron diffuser Burks lists as part 21157 at 5-1/2 in inside diameter, for Burks 10WA6 self-priming centrifugal pumps. It is the stationary ring of passages around the impeller that turns speed into head, and on a self-priming pump it also forms part of the recirculation path that clears air out of the suction line.
The diffuser wears in step with the impeller. Grit passing through erodes the passage walls and opens the clearance at the impeller tips, and liquid that should be carried forward leaks back toward the suction instead. On a self-priming pump the first symptom is often slow priming rather than low flow, because the same clearance governs how well the pump can clear air out of the suction line.
Material matters alongside size. Cast iron is what Burks specified for this version, the standard specification for general service, and the bore is 5-1/2 in inside diameter. Both need to match before you order.
Key Features
- Genuine Burks replacement diffuser in cast iron
- 5-1/2 in inside diameter - the dimension that identifies the part
- Fits Burks 10WA6 self-priming centrifugal pumps
- Restores the pressure conversion lost to worn passages
- Re-establishes the running clearance at the impeller tips
- Helps return priming performance on self-priming pumps
Applications
- Burks WA6 self-priming centrifugal pump rebuilds
- Restoring discharge head that has fallen away
- Curing slow or unreliable priming
- Repairing erosion damage from sand, scale or rust
- Replacing a diffuser alongside a new impeller
- Industrial, agricultural, marine and dockside installations
Specifications
- Brand: Burks
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 21157
- Part Type: Diffuser
- Material: Cast iron
- Size: 5-1/2 in inside diameter
- Fits: Burks 10WA6 self-priming centrifugal pumps
- Condition: New
Frequently Asked Questions
Q: Is the diffuser handed or can it go in either way round?
It has a definite orientation, set by the passage direction and the fastener positions. Note how the old one sits before it comes out, and follow the Burks service instructions when refitting.
Q: Should the impeller be replaced at the same time?
In most cases yes. The two wear together in the same liquid and it is the gap between them that makes the pressure, so a new diffuser running against a worn impeller gives back only part of the lost duty.
Q: How do I measure the wear?
Check the clearance between the impeller tips and the diffuser bore at several points around the circumference, and compare it against the figure in the Burks service literature. Uneven wear also tells you whether the rotating assembly has been running true.
Q: What is the difference between the iron and bronze versions?
They are dimensionally the same part in different materials. Bronze is specified where the liquid or the environment would attack cast iron, most obviously in brackish or salt-laden service, and is the usual choice on all-bronze pump builds.
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 diffuser before you order.
CLRMarine
