Galvanized Iron Fittings

Galvanized malleable iron fittings in 1/8" through 4", threaded NPT. Tees, couplings, bushings, 90° elbows, street and adapter elbows, and plugs, in FIP, MPT x FPT, three-way FPT and flanged patterns.

These are the same malleable iron castings used in black iron, finished with a hot-dip zinc coating. That coating is the whole difference: it buys external corrosion resistance for damp, exposed and outdoor runs, at the cost of internal flaking over long service life.

Do not use galvanized on interior fuel gas. Zinc shed from the coating travels downstream and fouls regulators, valves and burner orifices, and most codes prohibit it outright — black iron is the material for gas.

Where galvanized meets copper, install a dielectric union. The two metals in contact with water between them form a galvanic cell, and the steel side corrodes through at the joint well before either pipe reaches its normal service life.

Stocked from Mueller Streamline.

For 2" and larger steel pipe in fire protection and HVAC risers, Gruvlok grooved fittings and couplings join pipe without threading or welding.