the difference between long radius elbows and short radius elbows

Long radius elbows and short radius elbows will be connected with pipes, which can change the direction. These 2 types of elbows can be done with 30deg, 45deg, 60deg, 90deg, 180deg etc. And materials cover many steel grades of carbon steel, alloy steel and stainless steel. But do you know the difference between long radius elbows and short radius elbows? I will introduce it for you.

 the LR radius elbows have a center to end distance that is 1.5 times the NPS in inches(R=1.5D),while the SR radius is equal to the NPS in inches(R=1.0D). The 45, 90°and 180°elbows, all three in the "long radius" version, and in addition the 90° and 180° elbows both in the "short radius" version.

Dimensions, dimensional tolerances etc. for long and short radius elbows are defined in ASME B16.9. ASME B16.9 standardizes the center to face dimensions and some "squareness" dimensional tolerances.