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Galvanized malleable iron reducer coupling, 6 inch by 4 inch FNPT, Class 150

Anvil

Anvil 311093603 6" x 4" FNPT Galvanized Reducer Coupling

SKU CH-62JZ-V9SSS

A galvanised malleable iron reducer coupling joining 6-inch to 4-inch FNPT pipe, rated 300 psi at 150 °F and 150 psi saturated steam at 350 °F, meeting ASTM A197, ASME B16.3, FM and UL standards

  • Connects 6 in to 4 in pipe with FNPT threads
  • Galvanized malleable iron resists corrosion in water systems
  • Rated 300 psi at 150 °F for reliable pressure handling
  • Withstands saturated steam up to 150 psi at 350 °F
  • Meets ASME B16.3 and ASTM A197 with FM and UL approval

6" x 4" FNPT Reducer Coupling

The Anvil 311093603 joins a six-inch pipe to a four-inch pipe using female National Pipe Taper threads. Galvanized malleable iron construction meets ASTM A197 and ASME B16.3 standards for durability. It is suited for plumbing professionals assembling water, oil or gas distribution systems. FM Approved and UL Listed ratings support code-compliant installations.

Class 150 pressure and temperature envelope

The fitting handles 300 psi at 150 °F water, oil or gas and 150 psi saturated steam at 350 °F. Continuous service range spans -20 °F to 350 °F. Designers must size pumps and valves so that operating conditions stay inside these limits. Exceeding the rated pressure or temperature voids the FM and UL certifications.

Replaces same-size galvanized couplings

Swapping a straight coupling for this reducer eliminates an extra fitting and reduces potential leak paths. The jump is worth it when a system transitions from six-inch mains to four-inch branches and the installer wants a single, listed component. It does not serve applications that require a larger reduction or a different thread standard.

Highlights

  • Connects 6 in to 4 in pipe with FNPT threads
  • Galvanized malleable iron resists corrosion in water systems
  • Rated 300 psi at 150 °F for reliable pressure handling
  • Withstands saturated steam up to 150 psi at 350 °F
  • Meets ASME B16.3 and ASTM A197 with FM and UL approval

Specifications

BrandANVIL

Questions about this item

Should I choose the 6 in x 4 in reducer or a different size for my piping?

This fitting is a single 6 in x 4 in FNPT reducer coupling. Select it only when you need to join a 6 in pipe to a 4 in pipe with female NPT threads.

What does the 300 psi rating mean once the coupling is installed?

It handles up to 300 psi water, oil or gas at 150 °F and up to 150 psi saturated steam at 350 °F within the -20 °F to 350 °F range.

How does the FNPT connection and Class 150 standard limit the installation?

The female NPT threads accept male NPT pipe ends, and the Class 150 rating caps the maximum working pressure at 300 psi WOG per ASME B16.3.

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