The Importance of Quality Pipe Fittings

Aug 8, 2023 | Company News, News

When it comes to plumbing and gas systems, having the right pipe fittings is crucial for safety, performance, and longevity. Pipe fittings connect straight pipe sections and adapt them for changes in direction, size, or function. There are many types of pipe fittings, but three of the most common and useful are black iron pipe fittings, white heart pipe fittings, and malleable cast iron galvanized pipe fittings. Understanding when and how to use each type of fitting is important for any plumbing or gas system project.

Black iron pipe fittings

Black Iron Pipe Fittings

Black iron pipe fittings are made of black iron, which is a ferrous metal alloy with a black finish. The “black” color comes from the iron oxide coating that forms on the surface after hot rolling. Black iron pipe fittings include elbows, tees, couplings, caps, and more. They are available in a variety of sizes to fit different pipe diameters.

Black iron is strong, durable, and inexpensive, making black iron pipe fittings a popular choice for many residential and commercial gas and plumbing applications. They are commonly used for natural gas and propane gas lines, steam lines, compressed air lines, and fire sprinkler systems. The main downside is that black iron can corrode and rust over time when exposed to water. Therefore, black iron pipe fittings are better suited for indoor, dry applications rather than underground or wet areas. Proper installation and maintenance is key to preventing corrosion issues.

White Heart Pipe Fittings

White heart pipe fittings have a distinctive white ceramic interior coating. The white coating helps prevent buildup and corrosion. Common white heart fittings include tees, elbows, couplings, bushings and more. White heart fittings are made from malleable cast iron, which gives them added strength while still allowing some flexing and shaping during installation.

The glazed white interior creates a smooth, non-stick surface that improves flow. This makes white heart fittings well-suited for liquefied petroleum gas (LPG) lines and other applications where buildup in the pipe is a concern. The smooth interior helps prevent the formation of carbon deposits that could lead to flow restrictions.

Malleable Cast Iron Galvanized Pipe Fittings

Malleable cast iron galvanized pipe fittings combine the durability of cast iron with the corrosion resistance of a zinc galvanized coating. Malleable cast iron starts as standard cast iron, but it goes through an annealing process that transforms the brittle cast iron into malleable cast iron. This increases the ductility and impact resistance.

The galvanized coating is applied to the exterior and interior surfaces of the fitting. During the hot-dip galvanizing process, the iron fittings are submerged in a bath of molten zinc. The zinc bonds tightly to the iron, providing a protective layer against rust and corrosion. This makes galvanized fittings suitable for wet, underground, or chemical environments where uncoated cast iron would degrade more quickly.

Galvanized malleable iron fittings are commonly used for railings, roadside hardware, watersystem pipes, chemical lines, and structural applications. Common galvanized fittings include unions, elbows, tees, couplers, bushings and more. The zinc coating can degrade over time, so fittings might need to be re-galvanized after many years of use. Proper installation also helps maximize the life of the galvanized coating.

Choosing the Right Fittings

When selecting fittings, consider the type of pipe, the operating conditions, and the environment. Black iron fittings work well for dry indoor gas lines, while white heart fittings are better for gas lines prone to buildup. Galvanized fittings handle wet conditions well but can be overkill for a dry indoor application. Combining different types of fittings is fine as long as you use the right style and size for each pipe connection. Pay close attention to temperature and pressure ratings to ensure the fittings are properly rated for the application.

Investing in quality fittings from reputable manufacturers is also important. High-quality fittings not only perform better but also increase safety. Defective or substandard fittings could leak or even rupture. So while you might pay a little more for quality fittings, it is worth it for the peace of mind and added safety.