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Copper sweat union fitting with cup connections on both ends

Nibco, Inc.

Nibco, Inc. 633W 1 in Copper Union Trap

SKU CH-M7F6-1Y42B MPN 633W

A 1-inch wrot-copper union trap rated for 494 psi at 100 °F and up to 400 °F service temperature

  • TypeDrain Components
  • MaterialHAWA
  • Sweat-fitting union joins copper tube without threading
  • Rated 494 psi at 100 °F for high-pressure lines
  • Withstands 400 °F for hot-water or steam service
  • Wrot copper construction resists corrosion in potable systems
  • Straight union design simplifies in-line installation and maintenance

What this union does

The Nibco 633W is a straight sweat-fitting union made from wrot copper for joining two 1-inch copper tubes. It handles air, gases and potable water in residential or light-commercial plumbing systems.

Check before ordering

Verify that both pipe ends are 1-inch copper tube sized for sweat connections and that the system pressure will not exceed 494 psi at 100 degrees F. Confirm the operating temperature stays within the 400-degree F maximum and that local codes permit copper unions for the intended fluid.

Replaces threaded or flanged joints

This union replaces threaded adapters or flanged connections where a compact, soldered joint is preferred. The jump is worth it when you need a leak-tight copper-to-copper transition that can be disassembled for maintenance without cutting pipe.

Highlights

  • Sweat-fitting union joins copper tube without threading
  • Rated 494 psi at 100 °F for high-pressure lines
  • Withstands 400 °F for hot-water or steam service
  • Wrot copper construction resists corrosion in potable systems
  • Straight union design simplifies in-line installation and maintenance

Specifications

TypeDrain Components
MaterialHAWA
BrandNibco
Model633W 1

Questions about this item

What does the 633W 1 in copper union trap include and what must be purchased separately?

The package contains the straight sweat-fitting union made of wrot copper with 1 in cup connections on both ends. Copper tube, flux, solder and any required hangers or valves are sold separately.

How do I choose between the available versions of the 633W union trap?

The 633W model is offered in a single 1 in nominal size with identical cup-to-cup ends, so there are no alternative capacities or configurations to select from.

What does the 494 psi rating mean when the union is installed in a plumbing system?

It indicates the maximum operating pressure the fitting can withstand at 100 °F; at higher temperatures up to 400 °F the allowable pressure will be lower.

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