## 4 inch 90 degree elbow dimensions

The center to end is one dimension of 4 inch 90 degree elbow. How caculate the center to end?

For a standard pipe elbow such as 45 and 90 degree, elbow center to the end size can be found in the standard piping diagram. But most of the time, in the standard of 45 or 90 degree elbow, cutting the need to customize the elbow Angle.

The formula for calculating the distance between the center and the end of the elbow is as follows:

Elbow length (mm) = Tan (elbow Angle / 2) X elbow radius (mm)

**Where:**

For 90 degree long radius elbow, ASME B16.9 size the center to the end line in the table size is the same as the elbow radius. That's because the tangent of 90 PI over 2 is the tangent of 45 is 1.

Custom elbows are usually cut from 45 to from 90 degrees. But for a custom elbow less than 45 degrees, the elbow is usually cut from an existing standard of 45 degrees. The center dimensions of the 45 degree elbow in the dimension table must be divided by tangent (22.5) to obtain the elbow radius of the standard 45 degree elbow. Then we can use the above formula to obtain the elbow joint Angle of the custom degree.

Example 1:

Calculate the center to the end of the elbow dimension of the 4 inch pipe elbow of 60 degree, cut from 4 inch 90 degree elbow.

In ASME B16.9, the center to end of 90 degree elbow is 152 mm.

Length = Tan (60/2) X 152.

Length = 0.57735027 X 152.

Length = 87.757 or 88mm.**Example 2:**

Calculate the center to the end of the elbow dimension of the 4 inch pipe elbow of 30 degree, cut from the 45 degree LR elbow.

In ASME B16.9, the center to end of 45 degree elbow is 35 mm.

Elbow radius = 35 / Tan (22.5)

Elbow radius = 35/0.4142 = 84.5 mm.

Length = 0.26795 x 84.5

Length = 22.64 or 23mm.