BUTTWELD ELBOW 45/90/180 DEG.
ASME B16.9 buttweld elbows are manufactured in a wide range of dimensions (combinations of outside diameter and wall thickness) to fit ASME B36.10 and ASME B36.19 carbon, alloy and stainless steel pipes of any size between 2 and 48 inches (and above).
Buttweld elbows below 24 inches in diameter are produced by cutting, heating and bending seamless steel pipes; pipe elbows of larger sizes are manufactured, instead, from welded pipes or steel plates.
The three most common types of elbows in piping are the 45, 90, and 180 degrees (or return elbow), as shown in the image:
Types of elbows in piping
Some special types of pipe elbows are:
reducing elbow: a pipe connector with an inlet and an outlet in two different bore sizes is used instead of the combination of a standard elbow and concentric reducer.
mitered elbow: large size elbow assembled by joining steel plates