Delta application-to-part record
Delta Leland 9178-DST Cartridge: RP50587
RP50587 is Delta's documented cartridge for the Leland 9178-DST single-handle pull-down kitchen faucet. Confirm the complete application and concealed valve or faucet generation before purchase.
Direct answer
Use Delta RP50587 only when the fixture is confirmed as the Leland 9178-DST single-handle pull-down kitchen faucet. The 9178-DST model suffix is part of the identification; family name or spout shape alone is not enough.
Fit facts
What identifies this match
Use these details together. One matching feature does not establish compatibility.
- Manufacturer
- Delta Faucet
- Application
- Leland 9178-DST single-handle pull-down kitchen faucet
- Part number
- RP50587
- Fixture
- kitchen faucet
- Control
- single lever
- Valve or faucet technology
- DIAMOND Seal Technology faucet
- Generation marker
- the DST model application shown in Delta's model-specific product documentation
The documented application
Delta identifies RP50587 for the Leland 9178-DST single-handle pull-down kitchen faucet. That manufacturer relationship is the basis for this record; resemblance to another cartridge is not a fit claim.
Read the complete model or series designation. The 9178-DST model suffix is part of the identification; family name or spout shape alone is not enough.
Generation and control type come first
Establish whether the fixture is DIAMOND Seal Technology faucet and whether its control is single lever. Those attributes separate parts that may share a brand and similar exterior trim.
Treat installation year as supporting evidence, not proof. A remodel can retain an older rough valve or pair newer-looking trim with an existing compatible valve body. The removed cartridge, model documentation, and valve identity are stronger evidence.
What to inspect before ordering
Turn off the appropriate water supplies before exposing a cartridge. Record the complete model number, all suffixes, the trim designation, and any markings on the removed cartridge without forcing the valve apart.
Compare those observations with Delta's current part page and the model-specific parts diagram. If the installed valve cannot be positively identified, use Delta's product-identification service rather than ordering from a photograph alone.
- Match the full model or Monitor series, not only the collection name.
- Confirm pressure-balance versus thermostatic operation on shower controls.
- Compare retained features, stem arrangement, and documented part number.
What this match does not establish
This record does not make RP50587 universal across Delta products. Finish, handle silhouette, escutcheon shape, and approximate cartridge dimensions cannot override a different model or valve generation.
It also does not show that a different cartridge should be modified to fit. A mismatch is a reason to stop and re-identify the fixture, especially when an older and newer Monitor valve can sit behind similar-looking trim.
Questions
Before you remove or replace the part
Is RP50587 a universal Delta cartridge?
No. Delta documents it for the Leland 9178-DST single-handle pull-down kitchen faucet. Confirm that exact application and its generation before ordering.
Can I identify the cartridge from the visible handle and trim?
Not reliably. Similar trim can conceal different valve generations or control technologies. Use the full model, valve identity, removed cartridge, and official parts diagram together.
Does an approximate installation year prove compatibility?
No. The year can narrow the search, but retained rough valves and later trim changes make the physical valve and official model documentation more reliable.
What should I do if the model and removed cartridge disagree?
Pause the purchase. Photograph the markings and valve features, retain the old cartridge, and use Delta's identification service or support channel to resolve the conflict.
Reference trail