Delta RP50587 Cartridge Review: Compatibility, Replacement & Buying Guide
The genuine Delta RP50587 is the correct replacement cartridge for many—but not every—single-handle Delta kitchen and lavatory faucet with DIAMOND Seal Technology (DST). Confirm your faucet model before ordering.
Is the Delta RP50587 Worth Buying?
Yes—if the exact part number is listed for your faucet. RP50587 is Delta’s one-handle DIAMOND Seal Technology cartridge used in many DST kitchen and lavatory faucets. Delta describes it as a ceramic valve, and its parts finder lists a diameter of approximately 1-27/64 inches.
A cartridge is a fit-specific repair part, not a universal upgrade. The biggest purchasing mistake is choosing it by appearance alone. Several Delta cartridges look similar but differ in diameter, tabs, stem design, or faucet application. Verify the model number or faucet parts diagram first.
Genuine Delta RP50587 Cartridge
- Designed for compatible one-handle Delta DST faucets
- Ceramic-valve construction
- Better choice when exact fit and Delta support matter
- Not a universal Delta or shower cartridge
Best for
Owners whose Delta faucet documentation explicitly identifies RP50587 and who want the genuine OEM replacement.
Not for
Delta shower valves, two-handle faucets, older ball assemblies, Euro-motion cartridges, or any faucet listing a different part number.
Main advantage
Correct OEM dimensions and tabs reduce the risk of a fit problem compared with an unidentified look-alike.
Main limitation
The cartridge is not designed to be rebuilt with common seats-and-springs kits; a failed unit is normally replaced as an assembly.
Will RP50587 Fit Your Delta Faucet?
Delta says RP50587 is used on most single-handle motion DST kitchen and lavatory faucets—not all Delta faucets. Use this three-part check before buying:
- Find the faucet model. Check the original box, installation sheet, purchase record, or the supply-line tag under the sink.
- Open the official parts diagram. Search the model on Delta’s “Find Parts & Identify Your Product” page and locate the cartridge number.
- Match the full part number. Order RP50587 only when the documentation lists RP50587. Color alone is not decisive; Delta has documented black and gray upper-body versions.
| What you have | Is RP50587 likely? | What to do |
|---|---|---|
| One-handle Delta DST kitchen/lavatory faucet | Possibly | Confirm the exact faucet model and parts diagram. |
| Delta Touch2O or motion DST faucet | Common on many models | Still verify the model; “most” does not mean every model. |
| Two-handle faucet | No | Identify the hot and cold stem cartridges separately. |
| Tub or shower valve | No | Use the shower valve model/series to find its cartridge. |
| Older ball-style single-handle faucet | Usually no | Look for the correct ball assembly, seats, and springs. |
| Unknown faucet brand or model | Do not assume | Identify the manufacturer and model before removing parts. |
Genuine Delta vs Aftermarket RP50587
| Decision factor | Genuine Delta | Aftermarket replacement |
|---|---|---|
| Fit confidence | Highest when RP50587 is specified | Varies by maker and manufacturing tolerance |
| Manufacturer support | Delta product support applies | Support comes from the third-party seller/brand |
| Initial cost | Often higher | Often lower |
| Quality consistency | OEM specification | Can vary considerably |
| Best choice for | Long-term repair and fit assurance | Budget repair when reviews, return policy, and dimensions are verified |
For a faucet you intend to keep, the genuine cartridge is our preferred choice. An aftermarket version may save money, but verify the stated compatibility, seller reputation, return window, and included parts. Avoid listings that claim universal compatibility without naming specific Delta applications.
How to Replace a Delta RP50587 Cartridge
This is a typical overview for a compatible DST faucet. Your faucet’s official maintenance sheet takes priority because handle and cap designs vary.
Tools and supplies
- Correct replacement RP50587 cartridge
- Allen key or screwdriver that fits the handle fastener
- Adjustable wrench
- Soft cloth and a small container for parts
- Flashlight and towels
- Shut off both water supplies. Close the hot and cold valves under the sink. Open the faucet to relieve pressure, then cover the drain.
- Remove the handle. Loosen the correct set screw or fastener and lift the handle away. Photograph the orientation before taking more parts off.
- Remove the cap and bonnet nut. Protect the finish with a cloth. Use an adjustable wrench on the flat edges of the bonnet nut and turn carefully.
- Lift out the old cartridge. Note its orientation. Do not twist or damage the faucet body and integrated supply components.
- Clean the valve area. Remove loose mineral debris with a clean damp cloth. Do not scratch sealing surfaces or force tools into the valve body.
- Align the new cartridge. Seat its bottom tabs in the matching divots in the valve body. It should sit evenly; never force a mismatched cartridge.
- Reinstall and secure the bonnet. Refit the bonnet nut and tighten securely following the faucet’s official instructions. Avoid uncontrolled overtightening.
- Reassemble and test. Reinstall the cap and handle. Turn water supplies on slowly, operate the faucet, and inspect the handle, base, spout, and cabinet for leaks.
Ready to Replace the Cartridge?
Confirm RP50587 in your faucet’s parts diagram, then compare current availability. Amazon prices and stock can change.
See Latest RP50587 AvailabilityCommon Problems After Replacement
| Symptom | Likely check | Next action |
|---|---|---|
| Drip continues from spout | Cartridge alignment, debris, or wrong part | Shut off water, verify the tabs are seated and confirm the part number. |
| Leak under handle | Bonnet nut may not be secure | Follow the model instructions and check the bonnet before operating again. |
| Handle feels wrong or will not move normally | Incorrect orientation or mismatched cartridge | Do not force it; reopen and compare orientation with the diagram. |
| Low flow remains | Aerator, spray head, supply valve, or debris | Cartridge replacement may not address a downstream restriction. |
| Hot and cold behavior is reversed | Installation/orientation issue | Shut off water and recheck the model-specific assembly instructions. |
| Leak inside cabinet | Supply connection or faucet-body issue | Turn water off immediately, dry the area, and locate the exact source. |
How Long Does an RP50587 Last?
There is no responsible universal lifespan such as “two years.” Service life depends on water quality, mineral buildup, debris, water pressure, frequency of use, installation, and the condition of the faucet body. Replace the cartridge when a verified cartridge-related drip, stiffness, or control problem develops—not on a fixed calendar.
To reduce premature wear, avoid forcing the handle, address unusually high water pressure, keep debris out of open supply lines during plumbing work, and investigate leaks promptly.
Final Verdict
The genuine Delta RP50587 is a sensible repair when your exact one-handle DST kitchen or lavatory faucet specifies it. Its biggest strengths are OEM fit and access to Delta’s product-support ecosystem. Its biggest weakness is that it is frequently confused with other Delta cartridges and cannot be treated as a universal single-handle replacement.
Our recommendation: verify the model, contact Delta about possible warranty support, and then buy the genuine cartridge if RP50587 is confirmed. That sequence gives you a better chance of a correct, economical repair.
Check Current Availability on AmazonFrequently Asked Questions
Is the Delta RP50587 cartridge universal?
No. It fits many compatible one-handle Delta kitchen and lavatory faucets with DIAMOND Seal Technology, but it does not fit every Delta faucet. Confirm the cartridge number in your faucet’s official parts diagram.
Does RP50587 fit Delta shower faucets?
No. RP50587 is associated with compatible one-handle kitchen and lavatory DST faucets. Tub and shower valves use model- or series-specific shower cartridges.
Can an RP50587 cartridge be repaired with seats and springs?
Delta states that RP50587 is not designed to be serviced and does not have internal repair parts available. If the cartridge itself fails, replace the assembly.
Why is my replacement RP50587 black instead of gray?
Color alone does not prove it is wrong. Delta has documented production versions with a black upper body and black handle limit stop. Confirm the labeled part number and fit rather than relying only on color.
Do I need plumber’s putty on the RP50587 cartridge?
Do not add plumber’s putty around the cartridge unless the official instructions for your exact faucet specifically require it. Correct alignment, clean sealing surfaces, and proper bonnet installation are what matter.
Should I buy OEM or aftermarket?
OEM is the safer choice for exact fit and Delta support. An aftermarket cartridge may cost less, but its tolerances, materials, warranty, and quality control depend on the manufacturer.
Research Sources
Core compatibility and installation details were checked against Delta Faucet’s official RP50587 product page, common-parts finder, DST drip troubleshooting instructions, RP50587 color bulletin, and faucet warranty page. Always use the instructions for your exact faucet model.