Selection of steel hydraulic tube
with appropriate material and size
Hydraulic tubes should be selected according to system pressure, flow rate and application environment. Attention must be paid to whether the strength of the tube is sufficient, whether the diameter and thickness of the tube meet the requirements of the system, and the inner wall of the selected pipe must be smooth, non-corrosive, no oxide skin, no clamps and other defects. If any of the following problems are found on the hydraulic pipe, it shall not be used:
1. The inner and outer walls of hydraulic tubes are seriously corroded.
2. The scratch depth of the pipe body is greater than 10% of the wall thickness.
3. The surface of the pipe body is sagged to more than 20% of the diameter of the pipe.
4. The wall thickness is not uniform and the ellipticity is obvious.
In the application of medium and high pressure hydraulic system, seamless steel pipes are usually used, because they have the advantages of high strength, low price and easy leak-free connection, so they are widely used in hydraulic system.
Cold-drawn low-carbon steel tubes are usually used in common hydraulic systems, because carbon steel hydraulic pipes can be reliably welded to various standard fittings. For applications requiring corrosion resistance, such as hydraulic servo systems, common stainless steel seamless tubes are often used. Stainless steel hydraulic tubes have corrosion resistance, smooth internal and external surfaces, and accurate size.