Watts LF25AUB-Z3 1 1 In Lead Free Water Pressure Reducing Valve, Npt Female Union X Npt Female, Polymer Seat, Adjustable 25-75 psi

Connections are 1 inch NPT female on both the inlet and the outlet, so it mates with 1 inch NPT male threaded pipe or male adapters on either side. The inlet is a union connection, which means you can break the valve out of the line for service without cutting pipe or unthreading the whole run. On copper you will need male NPT sweat or press adapters at both ends.

The Z3 valve has a built-in thermal expansion bypass. That bypass relieves excess pressure back toward the supply when a water heater cycles and the system pressure on the house side climbs above inlet pressure, which is the usual cause of a weeping T and P relief valve on a closed system. It handles thermal expansion pressure, not thermal expansion volume, so if your jurisdiction or the heater manufacturer requires an expansion tank on a closed system, the bypass does not remove that requirement.

Yes. The body is a lead free cast copper silicon alloy and the valve is designated lead free, which is what puts it in the potable water category rather than the mechanical or non-potable one. That matters for anything downstream of a drinking water supply in a residence, school, healthcare facility, or commercial kitchen. It is also Buy American Act compliant, made in the USA, which is the box a government or institutional spec usually needs checked.

A stainless steel strainer is built into the valve, so you do not need a separate Y-strainer upstream just to protect the seat. On a well system or a line with heavy sediment you may still want additional filtration ahead of it, but on municipal supply the integral strainer is what keeps grit off the seat. Leave clearance at the strainer cap so the screen can be pulled and cleaned without dropping the valve out of the line.

Maximum operating temperature is 160 F, with a minimum of 33 F (0.5 C). That covers cold potable service and a domestic hot line running at a normal 120 to 140 F storage temperature. It is not for a line running above 160 F, and the 33 F minimum means it cannot be installed anywhere subject to freezing, so an unheated crawlspace or an exterior wall cavity needs to be insulated or heat traced.

Order the Watts LF25AUB-Z3 1. The LF prefix is the lead free body, the Z3 designates the version with the integral thermal expansion bypass, and the trailing 1 is the 1 inch size. It is also carried under Watts part number 9309. Both connections are 1 inch NPT female, with the union on the inlet.

They solve different problems. A reducing valve like the LF25AUB-Z3 sits at the service entrance and continuously holds downstream pressure at a set point, adjustable 25 to 75 psi here, so fixtures, ice makers, and flex connectors see a steady pressure instead of full street pressure. A relief valve does nothing until pressure exceeds its setting, then dumps water. If your problem is chronically high house pressure, blown supply lines, or noisy fixtures, the reducing valve is the fix. If it is only a water heater weeping on a closed system, the Z3 bypass in this valve addresses that too.

The disc is EPDM and the trim is an engineered composite rather than metal, with a corrosion resistant coating on the valve. EPDM is the standard elastomer for potable cold and hot water service and resists the chloramines used in most municipal treatment. The composite trim is what keeps the moving parts from scaling and seizing the way brass-on-brass trim can in hard water, which is why this style is common on maintenance replacements in multi-family buildings.