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Black cast-iron reducing coupling 6 inch by 3 inch FNPT threads

Legend Valve

Legend Valve 350-574 6" x 3" Reducing Coupling FNPT x FNPT

SKU CH-0WJ2-GWDFS

A 6-inch by 3-inch black reducing coupling with FNPT threads on both ends connects pipes of different diameters

  • Reduces pipe size from 6" to 3
  • Female NPT threads on both ends for secure connections
  • Black steel construction suits industrial plumbing systems
  • California Proposition 65 warning for cancer risk
  • California Proposition 65 warning for reproductive harm risk

Product Identity

This Legend Valve 350-574 reducing coupling connects a 6-inch female NPT pipe to a 3-inch female NPT pipe in black iron systems. It is intended for plumbers and contractors joining dissimilar pipe diameters in water, gas or oil lines where threaded connections are required.

Installation Context

The coupling threads directly onto both pipe ends without adapters, reducing the number of joints and potential leak paths. Its FNPT x FNPT design fits standard tapered threads, freeing installers from welding or flanging while maintaining a secure mechanical seal in compliant piping networks.

Sustained Service

The black iron construction resists mechanical stress and temperature cycling in continuous-pressure applications. California Proposition 65 warnings indicate the presence of chemicals linked to cancer and reproductive harm, so specifiers must verify material compatibility with local codes for long-term potable or hazardous-fluid service.

How it compares

Measured against everything we stock in Hose Fittings, Adapters & Clamps, at today’s prices. Recalculated every night.

Price $113.99
Pricier than about 90% of the 2,955 comparable items (median $17.99).

Specifications

Product
Brand nameLEGEND VALVE

Questions about this item

Will the 350-574 coupling leak or deform after months of continuous water pressure?

The black reducing coupling is rated for standard plumbing pressures; sustained use within design limits will not cause deformation.

Does the 6-inch by 3-inch cast-iron body get hot or noisy when water runs all day?

The fitting has no moving parts and does not generate heat or noise under normal flow conditions.

Must I already own 6-inch and 3-inch FNPT-threaded pipe to install this coupling?

Yes, both ends are female NPT threads, so matching male-threaded pipe or nipples are required for connection.

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