Approximate weight of a butt welding elbow can be calculated based on its its radius, wall thickness and angle. Please note that actual weight of a elbow from a particular manufacturer may vary depending on manufacturing process. Dimensional standards like ASME B16.9 do not provide weights of butt welding fittings. 

Weight of a Butt Weld elbow as per ASME B16.9 is calculated as per following formula  :

Where :

1. W = Weight in Kg
2. F = Center to End (mm)
3. D = Outside Diameter (mm)
4. T = Wall Thickness (mm)
5. θ = Angle

From Elbow	Long Radius 90 Degree Elbow Long Radius 45 Degree Elbow Short Radius 90 Degree Elbow 3D 90 Degree Elbow 3D 45 Degree Elbow
Elbow Size	1/2 3/4 1 1-1/4 1-1/2 2 2-1/2 3 3-1/2 4 5 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Elbow Angle
Wall Thickness	mm Inch