Watts LFN55BM1-U-S 1/2 IN Lead-Free Pressure Reducing Valve, Brass, Sweat

The Watts LFN55BM1-U-S 1/2 IN is a 1/2" lead-free pressure reducing valve with single union Sweat connections. It reduces inlet pressure of up to 400 psi to an adjustable 25-75 psi downstream, factory set at 50 psi. It features a brass body and a epdm seat. Rated to 400 psi and 33°F to 180°F. This model is certified lead-free for potable-water installations.

This 1/2 inch water pressure reducing valve is used in commercial and residential applications to reduce incoming water pressure for protection of plumbing system components and to reduce water consumption. It consists of a lead free brass body construction, solder union inlet by NPT female outlet connection, integral stainless steel strainer, thermoplastic seat, bronze sealed spring cage for accessible outdoor waterworks or pit installations and a thermal expansion bypass. The temperature range is 33 to 180 degrees F (0.5 to 82 degrees C). Suitable for up to 400 psi (27.6 bar), the pressure range can be adjusted from 25 to 75 psi (172 to 517 kPa) with the standard setting at 50 psi (345 kPa).

Features

• Solder union inlet by NPT female outlet
• Integral stainless steel strainer removable for cleaning
• Thermoplastic seat and bronze cage
• Corrosion-resistant adjusting screw and sealed cage for waterworks pit installations
• Includes: Strainer
• Includes: Bypass

Common Questions

Does it have a built-in bypass for thermal expansion, or do I still need an expansion tank?

LFN55BM1-U-S 1/2 IN includes an integral thermal-expansion bypass. When downstream pressure from a water heater rises above the inlet pressure, the bypass relieves that excess back through the valve toward the supply, which prevents nuisance pressure build-up on a closed system. It is not a substitute for a properly sized thermal expansion tank where your local code requires one - the bypass only relieves back to the street when street pressure is lower, so check the code in your jurisdiction.

What pressure is it set to out of the box?

LFN55BM1-U-S 1/2 IN ships factory set at 50 psi. The adjustable reduced-pressure range is 25 to 75 psi, so you can dial the outlet anywhere in that band on site with the adjusting screw - loosen the locknut, turn in to raise pressure and out to lower it, then retighten and verify with a gauge.

Does it include a strainer?

Yes - LFN55BM1-U-S 1/2 IN has an integral stainless steel strainer built into the body, so you do not need a separate inline strainer ahead of it. The strainer is removable for cleaning; if the valve starts to lose downstream pressure, pull and rinse the strainer before assuming the seat has failed.

Does it come with a gauge?

No - LFN55BM1-U-S 1/2 IN has no gauge and no gauge tapping. Set the outlet pressure using a gauge elsewhere on the downstream piping. The -GG version of this model ships with a gauge tapping and a 160 psi gauge.

Specifications

• Type: Pressure Regulator
• Size: 1/2"
• Inlet Size: 1/2"
• Outlet Size: 1/2"
• Connection: Sweat
• Body Material: Brass
• Seat / Seal Material: EPDM
• Max Pressure (psi): 400
• Shutoff: None
• Pack Quantity: 12
• Country of Origin: United States
• Warranty: 1 Year Limited
• MPN: LFN55BM1-U-S 1/2 IN
• Temperature: 33°F to 180°F
• Certifications: ASSE-1003, ANSI-A112.26.2, IAPMO
• Lead-Free: Yes
• Factory Set Pressure (psi): 50
• Adjustable Range - Min (psi): 25
• Adjustable Range - Max (psi): 75
• Thermal Expansion Bypass: Yes
• Integral Strainer: Yes
• Gauge: None
• Union Configuration: Single Union
• Capacity Class: High Capacity Full Port
• Regulated Media: Water