Jinan Acoustic Pipe manufacturers 18134186469- Zhao Lei -18,134,186,469 tubes commonly have steel pipe, steel bellows, three kinds of plastic pipe. Advantages of steel is easy to install, can be welded welded steel frame, but may replace some steel section, and because of the larger pipe stiffness. After embedding may be substantially parallel to maintain its flatness, many large-diameter steel pipe piles are used as an acoustic tube. But the price of steel is more expensive: steel bellows is a good acoustic tube material, it has a thin wall steel provincial and impermeability, pressure, high strength, flexibility and good features, typically used for prestressing post-tensioned structures reserved channels: make a sound when using the test tube. Can be directly tied on the steel skeleton, joints, bellows available larger size socket. Because the bellows is very light, so the operation is very convenient, but should pay attention to keep it straight when installing its axis. Low acoustic impedance of plastic pipe, with make a sound test tube with a larger sound transmission rate, typically used for smaller piles, should be used in a large pile of caution, because of the large diameter concrete piles require a lot of perfusion, heat of hydration of cement is not easy to diverge: Since the thermal expansion coefficient differences between plastic and concrete, plastic pipe due to temperature drop in radial and longitudinal shrinkage after the concrete has set, it is possible to make a partial disengagement of the concrete caused by air or water cracks in the sound path has added more highly reflective screen, likely to cause false positives. Acoustic tube diameter, and is usually higher than the radial transducer diameter l0mm to common specifications is the inner diameter of 50-60mm. Impact sound transmission rate of the wall thickness of the pipe is small, so, in principle, no restrictions on the wall thicknesses, but save steel consumption point of view, as long as the wall can withstand the lateral pressure of fresh concrete, the thinner the province.