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Malleable iron union coupling, dark metal finish, hexagonal nut, threaded ends

Anvil

Anvil 0312822687 Malleable Iron Union Class 300 coupling

SKU CH-9K3J-MGD2T

A 3/4-inch malleable iron union rated Class 300 with FNPT connections, brass seat, FM and UL approval, handling 600 psi at 150 °F and 230 psi saturated steam at 550 °F

  • Class 300 rating handles 600 psi at 150 °F for demanding piping systems
  • Brass seat resists corrosion and ensures tight sealing across temperature cycles
  • FM Approved and UL Listed for code-compliant fire protection installations
  • Meets ASME B16.39 standard guaranteeing dimensional accuracy and material quality
  • Operates from -20 °F to 550 °F including 230 psi saturated steam service

Anvil 3/4 inch Class 300 Union

The Anvil 0312822687 is a malleable iron union rated for Class 300 service. It connects 3/4 inch pipe via FNPT threads and carries FM approval and UL listing. The fitting meets ASME B16.39 standards for pressure piping systems. It suits industrial steam, water, oil and gas lines requiring a separable joint.

Installation uses the 1 3/16 inch hex

A 1 3/16 inch wrench fits the union hex for assembly. Apply thread sealant to the FNPT ends and tighten to the manufacturer torque value. The brass seat seals metal-to-metal without a gasket. Over-tightening can crack the malleable iron body or strip the tapered threads. Misaligned pipe runs stress the joint and cause leaks at the seat.

Pressure rating holds to 600 psi at 150 degrees F

The union withstands 600 psi at 150 degrees F and 230 psi saturated steam at 550 degrees F. Temperature range spans -20 degrees to 550 degrees F. Malleable iron and brass seat materials maintain integrity across this range under steady pressure. Cyclic thermal expansion may loosen the joint over time; periodic re-torquing preserves the seal.

Highlights

  • Class 300 rating handles 600 psi at 150 °F for demanding piping systems
  • Brass seat resists corrosion and ensures tight sealing across temperature cycles
  • FM Approved and UL Listed for code-compliant fire protection installations
  • Meets ASME B16.39 standard guaranteeing dimensional accuracy and material quality
  • Operates from -20 °F to 550 °F including 230 psi saturated steam service

Specifications

BrandANVIL

Questions about this item

How can I confirm the Anvil 0312822687 union is sealing correctly after installation?

Pressurise the system up to 600 psi at 150 °F or 230 psi saturated steam at 550 °F and check the brass seat for leaks; the FM Approved and UL Listed markings confirm it meets ASME B16.39.

What comes with the Anvil 0312822687 union and what must I supply?

The box contains the malleable iron union with brass seat, 3/4 in FNPT threads and 1 3/16 in hex; you must provide pipe sealant or tape and the mating pipe nipples.

Which class rating should I select for a 600 psi water line at 150 °F?

Choose the Class 300 version — it is rated for 600 psi at 150 °F and 230 psi saturated steam at 550 °F, covering that service condition.

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