What type of pipe threads are typically used in hydraulic lines?

Hydraulic lines typically use dryseal pipe threads, which are designed to create a leak-proof seal when connecting threaded pipes and fittings. The unique characteristics of dryseal threads include a more pronounced angle and a special profile that allows for tighter connections, making them especially suitable for high-pressure environments like those found in hydraulic systems. This ensures that fluid is contained effectively within the system, preventing leaks and maintaining operational integrity.

Other thread types do not offer the same level of sealing capability or strength required for hydraulic applications. National coarse and national fine threads are more commonly used for general fastening purposes rather than in pressurized fluid systems. National pipe taper threads, while similar, are typically not designed for the same level of leak-proof performance that dryseal threads provide. Therefore, dryseal threads are the preferred choice in hydraulic line applications due to their ability to withstand higher pressures and provide secure seals.