PIPING HAVING FLUID MIXING REGION

摘要

It is intended to, in a piping having a fluid mixing region where fluids of temperatures different from each other mix together, avoid any thermal fatigue attributed to fluctuation of temperature boundary plane. There is provided piping (1) including reducer (5) having its distal end portion (5e) arranged on substantially the central axis line of main pipe (2) and allowing low-temperature water having a temperature different from that of high-temperature water flowing outside the distal end portion (5e) and having a flow velocity lower than that of the high-temperature water to flow therethrough, wherein fluid mixing region (M) where the high-temperature water and the low-temperature water mix together lies downstream of the reducer (5), characterized in that the reducer (5) is provided with weld line (5f) joining the distal end portion (5e) with elbow portion (d) and that the distance between the weld line (5f) and downstream end (5a) is not smaller than the inside diameter (D) of the main pipe (2).