Hydronic piping and fittings can be made of which of the following materials?

Hydronic piping systems are essential for distributing hot water or steam for heating applications, which require specific material properties to function effectively. The correct answer includes steel, copper, and plastic as suitable materials for hydronic piping and fittings.

Steel is commonly used because it offers high strength and durability, capable of withstanding high pressures and temperatures typically found in hydronic heating systems. Copper is another popular choice due to its excellent thermal conductivity, corrosion resistance, and long lifespan. Plastic materials, specifically certain types such as PEX (cross-linked polyethylene), provide flexibility, ease of installation, and resistance to corrosion and scale build-up.

The other options include materials that either do not meet the necessary mechanical and thermal properties required for hydronic systems, or involve materials that are not commonly approved or used within such systems. For instance, aluminum and fiberglass, while useful in other applications, do not possess the same level of reliability and efficiency in heat exchange as copper or steel. Similarly, vinyl and PVC are generally not suitable for high-temperature applications typical of hydronics due to their lower temperature resistance and potential degradation over time. Wood is not a suitable material at all for hydronic applications, as it cannot withstand the demands of liquid transport in heating systems.