What Is PEX Tubing?
PEX tubing changed how plumbing and hydronic systems get built. Instead of cutting copper to size and sweating every joint, installers can run PEX through framing without fittings, reducing the chance of leaks. The tubing resists scale buildup, handles exposure to chlorine, and doesn’t corrode when touching concrete or soil. PEX carries pressure ratings of 160 psi at 73 °F and 100 psi at 180 °F, suitable for both cold and hot water lines. Crews often save 30 percent in labor by running continuous lengths with fewer joints.
Types of PEX Tubing (A, B, C, AL-PEX)
Each PEX type is cross-linked differently. Unlike copper pipe, PEX tubing allows for tighter bends, multiple installation methods, and reliable performance under pressure. Knowing the differences keeps jobs on spec and prevents callbacks.
PEX A: Made using peroxide. It is highly flexible with near-zero coil memory and is often used in radiant heating.
PEX B: Made with silane. It is stiffer, with high resistance to chlorinated water, and common in potable water systems.
PEX C: Electron-beam processed. It is cost-effective, with moderate flexibility.
PEX-AL-PEX: Includes an aluminum layer to limit thermal expansion. Good for long, hot water runs or snow-melt applications.
PEX Colors — Red, Blue, White, Orange, Purple
Color-coded tubing makes it easy to trace lines during rough-in, inspection, and repairs. Each shade signals a specific use, helping crews stay organized and code-compliant without second-guessing.
Red: Identifies hot water supply lines and boiler connections. It’s rated for frequent temperature swings and high heat.
Blue: Indicates cold water distribution to fixtures like sinks, toilets, and hose bibbs. Keeps plumbing layouts easy to follow.
White: A neutral option used for hot or cold lines, recirculation loops, or radiant and snow-melt systems where color isn’t specified.
Orange: Marks PEX-AL-PEX, the multilayer tubing with an aluminum core. Used in radiant and long hot water runs to reduce expansion.
Purple: Signals non-potable water applications—typically gray water or reclaimed systems—to prevent cross-contamination.
Every PEX tube includes printed details every four feet per ASTM F876 standards. These markings list size, pressure rating, and manufacturer, giving installers and inspectors the info they need at a glance.
PEX Fittings and Connection Systems
The way PEX connects determines how fast the job moves and how well it holds up over time. Matching the connection method to the jobsite conditions keeps projects efficient and callbacks low.
– Crimp rings: Slide a copper ring over the tubing, insert a barbed fitting designed for crimp connections, and compress the ring using a crimp tool. This method is widely accepted in both residential and commercial plumbing.
– Clamp rings: Use a stainless steel ring with a barbed fitting made for clamp installs. Position the ring over the tubing and secure it using a clamp tool. This method works well in tight spaces or when copper rings aren’t preferred.
– ProPEX expansion: Use an expansion tool to widen the tubing and fit a ring over it. As the material contracts, it forms a tight seal around the fitting—ideal for systems that experience frequent temperature changes.
– Press sleeves: Slide on a stainless steel sleeve, then compress it using a press tool. Known for consistent results and commonly used in large-scale or commercial installations.
– Compression fittings: Combine brass ferrules and nuts to form a tight seal. Works well when adapting PEX to copper or threaded components.
– Push-to-connect: Insert the tubing into a push fitting until it clicks. No tools required—this is the fastest option for emergency repairs or temporary setups.
Connecting PEX to Other Pipe Types
Jobs often call for bridging PEX to existing copper, PVC, PB, or fixture valves. Choosing the right transition fitting makes the connection safe, code-compliant, and built to last.
Copper: Use push-to-connect fittings with a stainless steel grip ring for quick retrofits. For a permanent solution, install a threaded sweat adapter or use press fittings designed to bond copper and PEX reliably.
PVC: Thread a male adapter into a solvent-welded PVC fitting, then connect the PEX side using a crimp or clamp system. Always check code requirements and use thread sealant where needed.
PB (polybutylene): Use transition fittings that include a built-in stiffener to support the PB tubing. These fittings stabilize the joint and help prevent leaks over time.
Fixtures: Secure a drop-ear elbow to framing with screws. Connect PEX using a crimp or clamp ring to keep the fixture valve fixed in place and resistant to movement.
Field Troubleshooting for PEX
Even well-installed systems can hit snags in the field. Most issues have straightforward fixes—if you know what to look for.
| Problem | Preventive Action | On-Site Fix |
| Kinks | Guide bends with a spring tool | Apply controlled heat to reshape, or cut and insert a coupling |
| Freeze alarms | Add pipe insulation and cable | Install heat-trace cable to prevent future freeze-ups |
| Uneven pressure | Bleed air from manifold zones | Balance flow manually or re-check each crimp for leaks |
| Weeping joints | Mark insertion depth clearly | Verify collar placement and re-crimp, or swap out the fitting |
| Stuck rings | Inspect tools and fittings often | Use a ring puller or cutter to safely remove and replace |
Use Cases: Where PEX Is Used
PEX tubing fits just as well in single-family builds as it does in large-scale commercial systems. Its flexibility, range of diameters, and compatibility with zoning make it a go-to material across applications.
Whole-house plumbing: Manifolds distribute water directly to each fixture, minimizing pressure drops and reducing the number of fittings in the wall.
Multi-family housing: PEX manifolds allow individual zoning per unit, which simplifies installation and maintenance while helping balance supply and demand across tenants.
Radiant heat: Oxygen-barrier PEX loops pair with radiant-floor manifolds to circulate heated water through slabs or joist bays, delivering even, efficient warmth.
Snow-melt: AL-PEX tubing is embedded beneath concrete or asphalt. When paired with snow-melt sensors, it activates automatically to prevent ice buildup.
Hydronic baseboard retrofits: PEX connects cleanly to hydronic baseboards, making it easier to modernize older systems with quieter, low-profile heat.
Why PEX Still Wins
PEX cuts install time, resists corrosion, and supports both hot and cold water lines. It connects easily to copper, PVC, and PB, and works across a wide range of systems, from radiant floors to whole-home plumbing. Choosing the right tubing, fittings, and layout from the start reduces rework and helps systems perform longer. Supplyhouse carries everything needed to keep jobs moving and everything to keep the job on track, including tubing, rings, press tools, expansion heads, and connection accessories.
