Piping and Tubing

 

Introduction

• Refrigerants, fuels, and fluids in heating and air-conditioning systems travel through piping or tubing.
• Working with different piping materials is crucial for air-conditioning and refrigeration technicians.

Types of Piping and Tubing Materials

• Common materials: Copper, iron, steel, aluminum, PVC, CPVC.
• Material choice depends on pressure, chemical compatibility, workability, and cost.
• Pipe vs. Tubing: Pipes are measured by inside diameter and schedule; tubing by outside diameter.

Steel Pipe

• Steel pipes come in various strengths (schedules 40 and 80 are common).
• Available in black iron and galvanized finishes.
• Steel pipe is named by its inside diameter and available in specific increments.
• Joining Methods: Welding, flanges, and threaded connections.
• Threading Steel Pipe: Threading involves cutting and fitting pipes using specific tools and techniques.

Cutting, Threading, and Joining Steel Pipe

• Threaded connections are common for steel pipes in air conditioning.
• Threading Steps: Cutting, reaming, applying thread-cutting oil, threading, and sealing with appropriate sealants.

Copper Tubing

• Types: Copper is available in different wall thicknesses (K, L, M) and is often used in ACR (Air Conditioning and Refrigeration) applications.
• ACR tubing is cleaned, degreased, dehydrated, and sealed for refrigeration use.
• Soft vs. Hard Copper Tubing: Soft copper is malleable, used for refrigeration lines; hard copper is rigid and used in commercial applications.

Cutting, Bending, and Joining Copper Tubing

• Copper tubing is cut with tubing cutters and bent using benders to avoid crimping.
• Joining Methods: Compression fittings, flaring, soldering, and brazing are used to connect copper tubing.

Making Flare Joints

• Flares are used to join soft copper tubing; R-410A compliant flares have larger chamfers to handle higher pressures.

Press Fittings

• Press fittings use rubber O-rings and require special tools for crimping, ideal for faster installation without needing a burn permit.

Plastic Pipe

• Common Types: PVC, CPVC, and HDPE are popular for their cost-effectiveness and ease of use.
• Joining Methods: Plastic pipes are typically joined using solvents that dissolve and fuse the pipe material.