Krök

Krök is a term used in Swedish and other Nordic languages to describe a curved section of a tube, pipe, hose, or duct that serves to change the direction of flow. In engineering and construction contexts, a krök is typically an elbow or bend defined by its angle and radius of curvature. The geometry is often described by the bend angle (for example 90, 45, or 180 degrees) and the centerline radius, with shorter radii producing tighter bends and potentially greater stress on the material.

Types and characteristics commonly include long-radius and short-radius krök, which differ in the radius of curvature relative to the pipe diameter. The choice between bend radii influences flow characteristics, pressure drop, and the risk of wall thinning or deformation near the inner bend. The inner and outer radii, wall thickness, and material properties are important factors in ensuring structural integrity under operating conditions.

Manufacturing and installation methods vary. Typical forming processes include mandrel bending, rotary draw bending, and roll bending. Mandrels help preserve cross-section and reduce wall thinning and springback. After forming, krök components may undergo finishing steps such as deburring, surface treatment, hydrostatic testing, or certification to meet relevant standards and specifications.

Applications span plumbing, heating, ventilation and air conditioning, automotive exhaust systems, hydraulic and pneumatic piping, and various industrial piping networks. Selection depends on space constraints, required bend angle, material compatibility, and pressure or temperature requirements. In Swedish technical language, krök corresponds to the English terms elbow or bend in piping components.