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Brass dielectric union with female NPT and sweat ends

Legend Valve

Legend Valve 301-120NL 3" FNPT x Sweat T-571NL Dielectric Union

SKU CH-W0BB-ZM2CF

Connects 3-inch female NPT pipe to sweat copper while preventing galvanic corrosion

  • 3-inch FNPT-to-sweat connection fits large-diameter plumbing systems
  • Dielectric union blocks galvanic corrosion between dissimilar metals
  • Lead-free construction meets potable-water safety requirements
  • T-571NL model ensures reliable sealing under pressure
  • California Proposition 65 warning discloses regulated chemical content

3" FNPT x Sweat Dielectric Union

The Legend Valve 301-120NL is a 3-inch dielectric union with FNPT threads on one end and a sweat connection on the other. It joins dissimilar metal piping while preventing galvanic corrosion in plumbing systems. The T-571NL model is supplied new and intended for professional installation.

T-571NL Model Designation

The T-571NL designation identifies the specific dielectric union configuration that determines material compatibility and pressure rating for the application. This model number is the single reference needed to verify the part matches the engineering specification. Selecting the correct T-571NL variant ensures the union meets the system requirements.

Installers Joining Dissimilar Metals

This union suits plumbers connecting copper to steel or iron pipe where dielectric isolation is required by code. It is not for installers needing a smaller or larger nominal pipe size, a different end-connection type such as threaded x threaded, or a union rated for a higher pressure class than the T-571NL provides.

Highlights

  • 3-inch FNPT-to-sweat connection fits large-diameter plumbing systems
  • Dielectric union blocks galvanic corrosion between dissimilar metals
  • Lead-free construction meets potable-water safety requirements
  • T-571NL model ensures reliable sealing under pressure
  • California Proposition 65 warning discloses regulated chemical content

Specifications

BrandLEGEND VALVE

Questions about this item

What does the 3-inch FNPT size mean for pipe compatibility?

The 3-inch female national pipe thread end connects to standard 3-inch male threaded pipe or fittings.

How does the sweat connection work with copper tubing?

The sweat end is soldered directly to 3-inch copper pipe for a permanent joint.

What clearance is needed to install this dielectric union?

Allow enough space to solder the sweat end and thread the FNPT side without stressing the union body.

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