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Stainless steel reducing coupling, 3 inch to 1-1/2 inch FNPT threads

Legend Valve

Legend Valve 404-399 3" x 1-1/2" SS304 Reducing Coupling

SKU CH-05D5-Z8FNS

A 304 stainless steel reducing coupling with FNPT threads joins 3-inch and 1-1/2-inch pipe

  • 304 stainless steel resists corrosion in harsh environments
  • Reducing design connects 3-inch to 1-1/2-inch FNPT threads
  • FNPT x FNPT threads allow direct pipe-to-pipe assembly
  • California Proposition 65 warning discloses regulated chemical content
  • New condition ensures full material integrity from factory

304 Stainless Reducing Coupling

The Legend Valve 404-399 is a 304 stainless steel reducing coupling designed for industrial plumbing systems. It connects a 3 inch female NPT thread to a 1-1/2 inch female NPT thread. The fitting suits installers who need a corrosion-resistant transition between dissimilar pipe sizes in water, oil or gas service. It is not intended for applications that require a straight coupling or a different material grade.

Sustained pressure performance

The 304 stainless construction maintains its mechanical strength and seal integrity under continuous operating pressure without the relaxation seen in softer alloys. Thread engagement remains consistent over long duty cycles, reducing the risk of weep paths that can develop with repeated thermal expansion. The coupling does not incorporate a gasket or sealing compound, so joint integrity relies on proper thread preparation and sealant selection by the installer.

Thermal and chemical resistance

Grade 304 stainless steel resists oxidation and scaling at elevated temperatures encountered in hot-water or steam lines up to the material's normal service range. The alloy also withstands exposure to many common industrial chemicals without pitting or galvanic corrosion when matched with compatible piping. No external coating is applied, so the fitting adds negligible thermal mass and does not contribute to insulation requirements. California Proposition 65 warnings apply for listed chemicals.

Highlights

  • 304 stainless steel resists corrosion in harsh environments
  • Reducing design connects 3-inch to 1-1/2-inch FNPT threads
  • FNPT x FNPT threads allow direct pipe-to-pipe assembly
  • California Proposition 65 warning discloses regulated chemical content
  • New condition ensures full material integrity from factory

Specifications

BrandLEGEND VALVE

Questions about this item

Does the SS304 material handle continuous high-temperature fluid flow without degrading?

The 304 stainless steel construction resists corrosion and withstands typical hot-water and steam temperatures found in industrial plumbing systems.

What thread type must my existing pipes have to connect directly to this coupling?

Both ends use FNPT threads, so your 3-inch and 1-1/2-inch pipes need matching female NPT connections for a direct fit.

Will the 3-inch to 1-1/2-inch reduction create turbulence that affects older galvanised pipe runs downstream?

The concentric FNPT-to-FNPT design provides a smooth bore transition that minimises turbulence in existing galvanised or steel piping.

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