How should the quality of finned tubes be inspected?

Finned tube is a kind of heat exchange tube, the main function is to improve heat exchange efficiency, usually on the surface of the heat exchange tube by adding fins, increase the external surface area (or inner surface area) of the heat exchange tube, so as to achieve the purpose of improving heat exchange efficiency, the detection method of the fin tube is not known to us, for this fin tube network experts said that there are two main methods, detailed as follows:

Analysis of the method of embedded detection of finned tubes

(1) Double fin tubes should be buried .0m pile diameter 6.0-8m; three fin tubes should be buried with a pile diameter of 0.8-2.0m; four fin tubes should be buried with a pile diameter of more than 2.0m, and three fin tubes can be buried in the pile foundation according to the specific conditions of Chifeng Bridge.
(2) Acoustic detection fin tube should use steel pipe, plastic pipe or steel bellows, and its inner diameter should be 50~60mm. The connection of the detection fin tube should be smooth and transitional, the fin tube mouth should be more than 100mm higher than the top of the pile, and the height of the tube mouth of each detection fin tube should be consistent, the lower end of the tube should be closed, the upper end should be covered, there should be no foreign matter in the fin tube, and the fin tube body should not be damaged.
(3) The detection fin tube can be welded or bundled on the inside of the steel bar, and the detection fin tube should be parallel to each other.

On-site detection

method for purchasing finned tubes
(1) Determine the delay time t of emission from the acoustic monitor to the receiving system before on-site testing. And calculate the sound time correction value.
(2) When measuring, the transmitting and receiving probes should be raised and lowered synchronously at the same elevation or maintain a fixed height difference.