What Size Is the Elbow on a 1.5″ Pipe? LR & SR Dimensions

ON May 6, 2026

In pipeline systems, when working with a 1.5-inch pipe (NPS 1.5), selecting the appropriate elbow is critical. One of the most frequently asked questions is: “what size is the elbow on a 1.5″ pipe?” The answer depends on the bend radius and manufacturing standard.

✅According to ASME B16.9, for butt-weld elbows, the “size” typically refers to the center-to-end distance. For a long radius (LR) 90-degree elbow, the center-to-end dimension is 1.5 times the nominal diameter (1.5 × 1.5 inches = 2.25 inches, approximately 57.2mm).

✅For a short radius (SR) 90-degree elbow, it is only 1 times the nominal diameter (1.5 inches, approximately 38.1mm). To obtain precise 1.5 inch pipe elbow dimensions, both bend radius and wall thickness schedule must be considered.

✅In practical installation, you also need to verify that the elbow’s connection end matches the pipe size. The actual outside diameter of a 1.5-inch pipe is 48.3mm (per ASME B36.10), and the elbow’s end outside diameter is the same. Regardless of whether you choose Sch40 or Sch80 wall thickness, the elbow’s end outside diameter remains unchanged, but the inside diameter will vary accordingly.

📌For example, a Sch40 elbow has an inside diameter of approximately 1.61 inches (40.9mm), while a Sch80 elbow has an inside diameter of approximately 1.50 inches (38.1mm). Therefore, the complete answer to “what size is the elbow on a 1.5″ pipe” includes two key parameters: bend radius and schedule series.

📌For the most common 90-degree applications, the typical 90 degree elbow center to face length is as stated above. However, if using a 45-degree elbow, the center-to-end dimension differs: for a 1.5-inch LR 45-degree elbow, the center-to-end length is approximately 0.875 inches (22.2mm).

✅Moreover, all dimensions strictly follow ASME B16.9 standard dimensions, which ensures global interchangeability. In confined spaces or low-pressure piping, short radius elbows save space, while long radius elbows are preferred for most industrial pipelines due to lower fluid resistance.

✅Additionally, note the difference in connection methods: the above dimensions mainly apply to butt-weld elbows. If your 1.5-inch pipe uses threaded (NPT) or socket-weld connections, you should refer to ASME B16.11 standards, where center-to-end dimensions often differ from B16.9 (e.g., the center-to-end length of a 1.5-inch 90-degree threaded elbow is approximately 38.1mm, but the effective thread length must be calculated separately).

📝As an engineering practice, always select elbows based on the pipe class and design drawings, and confirm the dimensional data sheet with the manufacturer before purchasing. By mastering these specific parameters, you can ensure proper assembly and long-term reliability of your piping system.