Sioux Chief 645X3GPK2 3/4" PEX...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$3.15
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

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Model: 645X3GPK2

In Stock (leaves warehouse same day if ordered before 3pm ET)

$3.15
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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.

Product Specs

Product Type:
Adapter
Connection Type:
Crimp
Country Of Origin:
United States
Department:
Plumbing
Product Group:
Rough-In and Supports
Product Subgroup:
Fittings and Valves
Product Size:
3/4"
Cubic Volume:
0.07578

Sioux Chief 645X3GPK2 – Frequently Asked Questions

1) How do I connect old 3/4 inch polybutylene supply line to new 3/4 inch PEX?
The Sioux Chief 645X3GPK2 is the transition fitting for exactly that joint: 3/4 inch PEX on one side, 3/4 inch PB on the other, crimped at both ends. It ships bagged with both rings, one natural copper ring for the PB side and one black copper ring for the PEX side, so you crimp each end with the correct ring and leave the rest of the PB run undisturbed.
2) Will the Sioux Chief 645X3GPK2 adapter work with any 3/4 inch PEX tubing?
No. The PEX side is specified for SDR9 tube only. If the 3/4 inch PEX on the job is a different dimension ratio, the crimp will not seat to spec and you need a different fitting. PB side is 3/4 inch nominal polybutylene supply line.
3) Do I need to buy crimp rings separately for a PB to PEX adapter?
Not with the 645X3GPK2. Each adapter is individually bagged with both rings it needs, one natural copper PB ring and one black copper PEX ring. PB and PEX rings are not interchangeable, which is the usual source of a failed crimp on this repair, so having the matched pair in the bag is the point of the part.
4) What tool do I use to make up this PEX to PB adapter?
It is a copper crimp ring connection on both ends, so it is made up with a crimp ring tool sized for the ring, not a press jaw, cone-and-nut compression, or expansion tool. Both the PB ring and the PEX ring supplied with the fitting are copper crimp rings.
5) Can I use this adapter to repair a failing polybutylene line behind a wall or under a floor?
That is the intended use. The 645X3GPK2 makes the PB-to-PEX cutover with one rough-in part, so a property manager or plumber can abandon a section of failing polybutylene and run PEX from that point without repiping the whole branch. Both joints are crimped, so plan on access for the crimp tool at the splice location.
6) How does the Sioux Chief 645X3GPK2 come packed for stocking a service truck?
One adapter with its two rings per bag, and 10 bags per case. That lets a plumbing contractor hand out single bagged kits for service calls or buy the case for a repipe where multiple PB branches are being cut over.
7) Is the Sioux Chief PB to PEX crimp adapter made in the USA for a government or institutional job?
Yes, the 645X3GPK2 is manufactured in the United States, which matters on procurement that carries a domestic-origin requirement.
How fast can I get the Sioux Chief 645X3GPK2 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Sioux Chief 645X3GPK2 come with a warranty?
Absolutely. The Sioux Chief 645X3GPK2 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Sioux Chief 645X3GPK2?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Sioux Chief 645X3GPK2 from ZenSupply?
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