Union: Malleable Iron, 3 in x 3 in Fitting Pipe Size, Female NPT x Female NPT, Class 300

Class 300 threaded fittings connect with medium- to high-pressure (300-3000 psi) pipe. Threaded fittings twist onto pipe using various male and female thread connections including NPT (National Pipe Thread) or BSPT (British Standard Pipe Taper).