In terms of fittings, what does the abbreviation "LR" stand for?

The abbreviation "LR" stands for Long Radius when referring to pipe fittings. In piping systems, long radius elbows are used to ensure a smoother flow of liquids or gases by minimizing turbulence that can occur with sharper bends. The long radius refers to the radius of the bend, which is typically one and a half times the diameter of the pipe. This design not only reduces pressure drop but also allows for more efficient fluid flow, making it preferable in many applications, especially those where maintaining flow efficiency is critical.

Choosing long radius fittings is especially beneficial in systems with more complex piping layouts where space allows. This contrasts with short radius fittings, which have a tighter bend and can cause increased friction and turbulence, potentially leading to inefficiencies. Therefore, the long radius designation is crucial for ensuring optimal performance and longevity in piping systems.