For what reason is flared fitting usage permitted for oil systems?

Flared fittings are often used in oil systems because they create a strong and reliable connection that can withstand high pressures. The reason that the use of flared fittings is permitted in these systems primarily stems from the fact that they provide a secure and leak-resistant joint. The flared design helps distribute the forces that occur during operation, which minimizes the possibility of leaks, especially critical in systems handling oil and other fluids.

Additionally, flared fittings can be easier to seal correctly compared to other types of fittings. They ensure a tight connection when properly installed, significantly reducing the chances of oil leaking under fluctuating pressure and temperature conditions present in an oil system.

While cost-effectiveness, ease of disassembly, and certain restrictions on compression fittings may seem relevant, the primary justification for using flared fittings in oil systems centers around their structural integrity and leak prevention capabilities.