Sioux Chief 645X3GPK2 3/4" PEX to 3/4" PB Adapter with Crimp Rings

Sioux Chief 645X3GPK2 3/4" PEX to 3/4" PB Adapter with Crimp Rings

The Sioux Chief 645X3GPK2 is a 3/4" PEX x 3/4" PB transition adapter built for taking an existing polybutylene (PB) supply line over to PEX tubing without cutting into new pipe runs. It is engineered for use with PEX SDR9 tube only, and each adapter is bagged with the crimp rings needed for both ends: one natural copper PB crimp ring and one black copper PEX crimp ring. The fitting is manufactured in the United States, so a plumber can transition a failing PB line to PEX behind the wall or under the floor with a single rough-in part instead of piecing together separate rings and adapters.

Key Features

• Trade Size: 3/4" PEX x 3/4" PB, sized for common polybutylene supply line diameters found in residential rough-in.
• Crimp Connection: Designed for use with PEX SDR9 tube only, giving a consistent crimp connection on the PEX side of the transition.
• Rings Included: Each adapter is bagged with one natural copper PB crimp ring and one black copper PEX crimp ring, so both ends of the connection are ready to crimp on arrival.
• Built for PB-to-PEX Transitions: Purpose-made for adapting old polybutylene lines to new PEX tubing runs, a common repair when PB supply lines are being phased out.
• Country of Origin: Manufactured in the United States.
• Packaging: Individually bagged one adapter with rings per bag (1/BG), packed 10 bags per case (10 BG) for jobsite and stock convenience.

Technical Specifications

• Trade Size: 3/4" PEX x 3/4" PB
• Tube Compatibility: PEX SDR9 tube only
• Rings Included: 1 natural copper PB crimp ring, 1 black copper PEX crimp ring
• Country of Origin: United States
• Packaging: 1 adapter per bag (1/BG); 10 bags per case (10 BG)

Typical Applications

• Polybutylene (PB) to PEX Line Repairs
• Residential Rough-In Plumbing Repairs
• Remodel and Renovation Plumbing Upgrades
• Replacing Failed or Aging PB Supply Lines
• Behind-the-Wall and Under-Floor Tubing Transitions

Why Sioux Chief?

Sioux Chief builds this adapter specifically for the PB-to-PEX transition job, pairing the fitting with the correct copper crimp ring for each side of the connection so installers are not left sourcing rings separately. Bagging one natural copper PB ring and one black copper PEX ring with every adapter keeps the rough-in kit complete and reduces callbacks caused by mismatched rings. Manufactured in the United States, the 645X3GPK2 gives plumbers and contractors a straightforward, purpose-built way to retire old polybutylene lines in favor of PEX tubing.