Skydrol 500B-4 Fire Resistant Aviation Hydraulic Fluid

Skydrol 500B-4 is the most worker friendly of the aviation phosphate esters; it is least irritating to skin and less prone to form mists which can be irritating to the respiratory tract. It has the longest service history of any phosphate-ester product. The original formulation, Skydrol 500, was first introduced in 1952, with steady improvements made over the years until the release of its current version in 1977. This version contains the same breakthrough anti-erosion additive and acid scavenger found in Skydrol LD-4, which has contributed to its widespread popularity, particularly in workshops and indoor test stands. Skydrol 500B-4 is primarily used in aviation hydraulic systems.