Sioux Chief 645XC Series Dual-Material CPVC x PEX Transition Coupling

Sioux Chief 645XC Series Dual-Material CPVC x PEX Transition Coupling

The Sioux Chief 645XC Series is a line of dual-material CPVC x PEX transition couplings built to join underground PEX water service lines to CPVC in-house piping at the point where the service line enters the structure. The family spans three coupling models — 645XC2, 645XC3, and 645XC4 — covering sizes from 1/2" to 1", so plumbers can match the coupling to the CPVC and PEX line sizes on the job. Each coupling accepts a CPVC connection on one end and a PEX connection on the other, completing the material transition in a single dual-material fitting instead of stacking field-fabricated adapters. Manufactured in the USA and packaged 20 pieces per case, the 645XC Series is built for straightforward distributor and contractor stocking.

Key Features

• Size Range: Available in 1/2", 3/4", and 1" sizes across the 645XC2, 645XC3, and 645XC4 models to match CPVC and PEX line sizes on the job.
• CPVC-to-PEX Transition: Purpose-built to connect underground PEX water service lines directly to CPVC in-house piping at the point of entry, without an intermediate material.
• Dual-Material Coupling Body: One coupling body accepts a CPVC connection on one end and a PEX connection on the other, eliminating the need for a separate adapter fitting or extra union at the transition.
• Quick, Easy Installation: Delivers a quick and easy transition between pipe materials, simplifying service-line hookups for plumbing contractors on new construction and repair work.
• Made in the USA: Manufactured in the United States, supporting domestic sourcing requirements on applicable jobs.
• Case Packaging: Packaged 20 pieces per case for efficient distributor stocking and contractor truck inventory.

Technical Specifications

• Series: 645XC (Models 645XC2, 645XC3, 645XC4).
• Size Range: 1/2" to 1".
• Coupling Material: Dual-Material CPVC/PEX construction.
• Country of Origin: United States.
• Case Packaging: 20 pieces per case.

Typical Applications

• Underground PEX Water Service Line Connections
• CPVC In-House Plumbing Systems
• Residential and Commercial Water Supply Transitions
• New Construction Water Service Installations
• Plumbing Renovation and Repipe Projects
• Point-of-Entry Material Transitions at the Foundation Wall

Why Sioux Chief?

Sioux Chief engineers the 645XC Series to give plumbing professionals a straightforward, dependable way to transition between CPVC and PEX piping without improvising a field workaround at the service entry. Manufactured in the United States and packaged in case quantities of 20 for job-ready stocking, the 645XC Series spans three coupling models — 645XC2, 645XC3, and 645XC4 — covering sizes from 1/2" to 1" so contractors can match the correct CPVC x PEX size to underground service entries and in-house distribution runs alike. Choosing a purpose-built dual-material transition coupling over field-fabricated adapters helps installers keep the CPVC-to-PEX connection quick, consistent, and easy to inspect on both new construction and repipe projects.