American Standard Reliant Plus Bath Shower Pressure Balance Cartridge - AMS-51091

Just the cartridge. 051091-0070A is the pressure balance cartridge on its own, catalogued as a repair part, so handles, escutcheon plates, screws, and tub spouts are separate orders. If you're doing a full refresh on the wall, plan on ordering the trim kit alongside it; if you're only chasing a temperature or drip problem, the cartridge by itself is usually the whole fix.

For openings that are genuinely Reliant Plus pressure balance valves, yes, this is the one part number to shelf: 051091-0070A. That's the case a property manager wants, one SKU on the truck instead of a trip per unit. What it will not cover is a different American Standard series in the same building, or a thermostatic or two handle valve, since those take their own internals. Pull one existing cartridge and match it before you buy the case.

That's the classic symptom of a failed pressure balance element, and on a Reliant Plus valve the balancing spool lives in this cartridge, so replacing 051091-0070A is the repair that addresses it. Swapping the cartridge is a whole lot less work than opening the wall, so it's the first move before anyone talks about replacing the valve body.

Finish doesn't apply. The cartridge is an internal working part that sits inside the valve body behind the escutcheon, so it ships with no finish and nothing about it is visible once the trim plate is back on. Whatever finish your Reliant Plus handle and escutcheon are, this same cartridge is the one that goes behind it.