180-degree return

A 180-degree return reverses the piping direction through a return or U-turn geometry, leaving its two ends oriented in opposite directions. It is distinct from 45- and 90-degree elbows and does not automatically mean two separate elbows or a heat-exchanger return bend. Leg spacing, pattern radius, matching end diameter and wall, material, weld access, and thermal-expansion loads should be reviewed for selection. The term return bend is also used in industry, but final geometry and dimensions must be confirmed by project drawings and specifications.