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Small malleable iron pipe union with threaded ends, dark metal finish

Value Brand

Value Brand 1/4" Malleable Iron Union Class 300 FNPT

SKU CH-46T1-GJPHP

A 1/4-inch malleable iron union rated for 600 psi at 150°F with FNPT threads

  • Handles 600 psi at 150 degrees F for high-pressure systems
  • Rated to 300 psi saturated steam for steam-line service
  • Operates from -20 to 450 degrees F across wide temperature swings
  • Built to ASME B 16.39 and ASTM A197 standards for code compliance
  • Malleable iron construction resists cracking under mechanical stress

What this fitting connects

The Zoro Select malleable iron union joins two 1/4 inch FNPT pipe ends in a straight line. It meets ASME B 16.39 and ASTM A197 standards for threaded pipe fittings. The Class 300 rating supports saturated steam service up to 300 psi. It is not for applications that require a reducing union or a different thread standard.

Pressure and temperature envelope

Maximum non-shock pressure is 600 psi at 150 degrees F. Saturated steam pressure is limited to 300 psi. The material remains rated from minus 20 degrees F up to 450 degrees F. Systems that exceed these pressures or temperatures need a higher-class fitting.

Upgrade from lower-class unions

This union replaces Class 150 malleable iron unions when the design pressure or steam load exceeds the lower rating. The jump is worth it when the piping specification calls for Class 300 threaded joints. It does not replace flanged connections or welded joints required by code.

How it compares

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

Price $16.99
Typical for this category: the median of 2,955 items is $17.99.

Specifications

Product
Brand nameZoro Select

Questions about this item

How do I choose the right class and size for my piping system?

Select this union when your design calls for a Class 300 fitting with a 1/4 inch FNPT connection; the malleable iron body meets ASME B16.39 and ASTM A197 for that rating.

What does the 600 psi rating mean once the union is installed?

It indicates the maximum non-shock pressure the joint can hold at 150 °F; at higher temperatures the allowable pressure drops, and saturated steam service is limited to 300 psi.

How does the FNPT thread standard affect what I can connect?

The Female National Pipe Taper threads seal with matching 1/4 inch MNPT nipples or pipe, and the Class 300 rating caps the assembly at 600 psi for water, oil, or gas at 150 °F.

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