What is the maximum allowable percentage of dents in the remainder of a hydraulic tube diameter?

The maximum allowable percentage of dents in the remainder of a hydraulic tube diameter is set to ensure the strength, integrity, and safe functioning of hydraulic systems. A value of 20% allows for a relatively high tolerance for manufacturing or handling imperfections, recognizing that some dents can occur during normal use without compromising the hydraulic tube's ability to withstand pressure.

Hydraulic tubes must maintain sufficient wall thickness and structural integrity to handle the pressures they will encounter. If the dent limit were lower, such as 10% or 15%, there would be a stricter tolerance on manufacturing imperfections, which could increase production costs and wastefulness without significantly enhancing safety.

Meanwhile, a limit of 25% would be too permissive, likely leading to more serious structural integrity issues, potentially resulting in hydraulic failure due to insufficient material to handle the operational pressures. Thus, the choice of 20% strikes a balance between operational safety and practical manufacturing considerations, allowing for some imperfections while ensuring that the tubes remain functional and safe for their intended applications.