Sta-Rite U9-199 Diffuser
This is the U9-199 diffuser. Because it channels every gallon the impeller moves, a cracked or worn diffuser shows up as reduced pressure, an external leak at the pump body, or a rattling noise even when the impeller itself is in good shape.
Cracks and chips in a plastic diffuser usually come from age and thermal cycling, from a pump that has been run dry, or from sand and grit wearing away the wall thickness over years of service. Inspect the o-ring or gasket surface where it seals against the pump body at the same time, since that surface is easy to nick during disassembly.
Key Features
- Genuine-fit Sta-Rite U9-199 replacement diffuser
- Directs impeller output into a smooth, pressurized flow toward the discharge
- Direct fit replacement for the original Sta-Rite part
Applications
- Restoring lost pressure on a Sta-Rite pump with a cracked or worn diffuser
- Rebuilding the Sta-Rite pump this part is cataloged for
- Routine wear-part replacement during a pump rebuild alongside the impeller and seal
- Fixing an internal leak or recirculation loss inside the pump body
Specifications
- Brand: Sta-Rite
- Manufacturer Part Number: U9-199
- Part Type: Diffuser
- Quantity Per Pump: 1
- Condition: New
Frequently Asked Questions
Q: Should I replace the impeller at the same time?
Inspect it while the pump is open. The diffuser and impeller wear under the same conditions, so it is common to replace both during one rebuild rather than opening the pump twice.
Q: Does this come with a new o-ring or gasket?
This listing is for the diffuser itself. Check the sealing surface on the old part and order a matching o-ring or gasket separately if it is worn, cracked, or was damaged during disassembly.
Q: Will this fit a different horsepower pump in the same series?
Match the exact part number on the old part rather than assuming pumps of similar size share the same component.
Q: What causes a diffuser to crack?
Age, thermal cycling, running the pump dry, and years of sand or grit passing through the water all contribute. A sudden crack after a hard freeze is also common on pumps left full of water in cold weather.
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.
CLRMarine
