Long radius elbow means that the radius of curvature of the elbow is 1.5 times of the pipe diameter; Also known as 1.5D.

Intuitively, the long radius elbow is much longer than the short radius elbow, and the bending radius of the elbow is relatively mild. Long radius elbow is the most commonly used elbow. Generally, long radius elbows will be used in places with high pressure or high flow. If the resistance requirements of solid conveying pipeline are strict, elbows with large radius shall be used.

Short radius is usually used for low-pressure fluid or limited elbow. If there are no conditions or provisions in the contract, long radius elbows are preferred.