Skills / Pipe Fitting (PEX/Copper/PVC) / Introduction to Pipe Fitting (PEX, Copper & PVC) / Pipe Fitting Basics: Materials, Joints, and When to Use Each
Pipe Fitting (PEX/Copper/PVC)

Pipe Fitting Basics: Materials, Joints, and When to Use Each

45 min read Training Guide

The three piping materials plumbers use every day (PEX, copper, PVC), how to make joints in each, and which to pick for a given application.

Table of contents

What the work looks like

Pipe fitting is the bread and butter of residential and commercial plumbing. A plumber on a rough-in job runs hot and cold supply and drain/waste/vent (DWV) between the water heater and every fixture in the building. The material choice is driven by application (potable supply, waste, gas, chilled water), pressure, temperature, code, and cost.

Safety and tools

PEX (crosslinked polyethylene) for supply:

  • PEX-A expansion fittings (Uponor ProPEX): expand the pipe, insert the fitting, and the pipe shrinks back for a reliable joint.
  • PEX crimp fittings (copper rings with go/no-go gauge).
  • PEX cinch/clamp fittings (one-eared stainless clamps).
  • Run with long sweeping bends. Pink (hot) and blue (cold) identification for installer clarity. UV-sensitive, so no outdoor exposure unless rated.

Copper Type L and Type M:

  • Sweat-solder joints: clean fitting and pipe, flux, 95/5 lead-free solder, MAPP or propane torch. Heat the fitting (not the solder), let capillary action pull solder into the joint.
  • Press fittings (Viega ProPress, Apollo press): insert fitting, press with certified tool, no flame. Faster and safer but fitting cost is higher.
  • SharkBite (push-to-connect): disposable inserts for fast repairs. Many jurisdictions do not allow them concealed.

PVC and CPVC:

  • Schedule 40 and 80 PVC for DWV (drain, waste, vent). Purple primer, cement on both parts, quarter-turn and hold 30 seconds.
  • CPVC for hot water supply in some regions. Separate (often orange) primer and cement.
  • Do not mix PVC cement on CPVC or vice versa.

Tool kit:

  • PEX expansion tool (Milwaukee or Uponor) or crimp tool.
  • Tubing cutter (copper and PEX have different blades).
  • Deburring tool (essential to prevent joint failure).
  • Propane or MAPP torch and fire blanket.
  • PVC ratcheting cutter (faster and cleaner than a saw).
  • Sandcloth or emery, flux brush, flux, solder.

Safety: torch work near wood framing requires a fire blanket or metal heat shield and a visual check 30 minutes after the last flame. Have a water bottle or extinguisher in arm's reach.

Your first exercise

At a hardware store, pick up one 10-foot stick of 1/2-inch PEX, one piece of Type L copper, and one stick of 1/2-inch PVC. Cut each with the appropriate cutter and examine the end quality. Compare the weight, feel, and cost. That tactile familiarity pays off on the job.

Where to go next

Build on Pipe Fitting (PEX/Copper/PVC) with Plumbing Fundamentals (Introduction to Plumbing), Plumbing Code Basics (Introduction to Plumbing Code), Fixture Installation & Repair, Water Heater Installation, Drain Cleaning, Gas Line Installation Basics (Introduction to Gas Line Installation). Soldering & Brazing from the Manufacturing category also reinforces joint-making fundamentals.