AMSE B16.11 Threaded 45 Degree Elbow

What is threaded 45° elbow? 

The 45-degree elbow is a pipe fitting with female National Pipe Taper (NPT) threads used to connect two pipes to change the flow direction.

Sino Special Metal supplys ASME B16.11 High Pressure 2000/3000/6000/9000 forged carbon steel/stainless stel/alloy steel/nickel alloy steel pipe fittings cross threaded fittings.

Asme B16.11 Threaded 45° Elbow Dimensions