This Standard relates to two grades of petroleum base hydraulic fluid :

Hydraulic fluid , petroleum, super clean, is for use in aircraft and other critical systems where a high degree of fluid cleanliness is required. It is suitable for use in unpressurized hydraulic systems operating between minus 54°C and plus 90°C and between minus 54°C and plus 135°C in pressurized systems.

Hydraulic fluid , petroleum, normal, is for use in non-critical systems and other applications not requiring the high degree of cleanliness of the super clean grade. It is suitable for use in unpressurized hydraulic systems operating between minus 54°C and plus 90°C and between minus 54°C and plus 135°C in pressurized systems.