1. No. 10 Aviation Hydraulic Oil (YH-10)

• Technical Standards: Complies with SH 0358-1995 (China Petrochemical Industry Standard), divided into aircraft-grade (for onboard systems) and ground-grade (for airport equipment).

• Key Features:

• Low-temperature performance: Operable down to -70°C, widely used in hydraulic systems of fighters (e.g., J-11, J-16) for landing gear and flight control surfaces .

• Mineral-based (red color), with excellent oxidation stability and anti-wear properties.

2. No. 15 Aviation Hydraulic Oil (YH-15)

• Technical Standards: Complies with GJB 1177(A)-1991(2013) (Chinese Military Standard), equivalent to MIL-PRF-5606H.

• Key Features:

• Higher purity for advanced hydraulic systems (e.g., fly-by-wire controls in J-10 and J-20).

• Gradually replacing YH-10 in newer-generation fighters due to improved low-temperature fluidity .

3. Fire-Resistant Hydraulic Oils

• RP4350 Synthetic Hydrocarbon Fire-Resistant Hydraulic Oil:

• High-temperature tolerance: Up to 220°C, used in missile servo systems and high-risk fire zones (e.g., engine bays of J-20 stealth fighters) .

• LD-4 (Phosphate Ester-Based Fire-Resistant Hydraulic Oil):

• Flash point: 175°C, originally developed by Skydrol (now produced by Eastman), adopted for critical systems requiring extreme fire resistance .

Application Scenarios

Technical Trends

• Shift to Fire-Resistant Oils: Driven by higher thermal loads in modern fighters (e.g., fifth-gen J-20).

• Domestic Production: Key suppliers include CNPC Yumen Refinery (YH-10/YH-15) and state-backed R&D for RP4350 .

For detailed specifications, refer to GJB 1177 (Chinese Military Standards) or consult authorized suppliers .