What material should be used for fittings in gas tubing systems?

Forged flare fittings are the preferred material for fittings in gas tubing systems due to their durability and ability to provide a tight seal under high pressure and temperature conditions commonly found in gas systems. These fittings are designed with a conical flare that creates a secure joint when connected to the tubing, minimizing the risk of leaks. The forged construction also ensures that they can withstand the mechanical stresses that gas systems may encounter.

In contrast, plastic fittings are not suitable for gas applications because they may not withstand the high temperatures and pressures encountered in these systems, potentially leading to failure and hazardous situations. Brass fittings, while often used for various plumbing applications, may not be as strong or leak-proof as forged flare fittings specifically designed for gas service. Unfinished metal fittings are also inappropriate because they lack the necessary protection against corrosion and may not meet safety standards for gas applications.