The Surprisingly Interesting Details of Flare Fittings

Admittedly, it’s hard to get overly excited about valves and fittings. But many fittings — meaning the various pieces used to connect lengths of pipe — are really quite ingenious. Consider the simple yet incredibly effective flare fitting:

What Are Flare Fittings?

Flare fittings are a specialized type of compression fitting. They’re usually used to join together thin-walled metal tubing (most commonly soft steel, soft copper, and aluminum, though they may be applied in a few other cases). This is accomplished by using a flared nut to secure tapered tubing to a tapered fitting. That may not sound like much, but this kind of connection is leak-tight and very reliable even over long periods of time. For that reason, it’s often used in mission-critical locations. You might be wondering why you wouldn’t just solder a mission-critical joint. The answer is that flare fittings can be easily applied in inaccessible locations, and can also be used in places where an open flame would be unsafe.

Why Brass Flare Fittings?

If you’re looking at your choices of flare fittings, you’ll see they can be made of a few different materials. The premier choice is generally brass. That’s because brass, as an alloy of copper and zinc, is strong, ductile (meaning it can be worked under tensile stress), and non-magnetic. Brass flare fittings are used particularly often with copper piping.

Should They Be Lead Free?

There are both leaded and lead free versions of most kinds of compression fittings. When lead is added to brass, it’s in a relatively low concentration — normally around 2% — to harden the alloy. Although it’s very unlikely that such a low level of lead would be harmful to anyone, regulators have decided out of an abundance of caution that lead free compression fittings must be used on any system that transports drinking water. Fittings are deemed “lead free” as long as they contain than 0.25% of lead on average.

Why are you looking into flare fittings? Join the discussion in the comments.