In the core components of aircraft engines or high-pressure reactors, piping systems are among the most vulnerable. Key pain points for engineers and procurement managers include:
Vibration-induced fatigue: High-frequency vibrations in engines can cause microcracks in ordinary piping, potentially leading to explosive leaks.
Pressure rupture at high temperatures: Many alloys lose their circumferential strength above 500°C. At 700 bar pressure, substandard piping can expand and rupture.
Internal scaling: Oxidation inside the piping can clog sensitive fuel injectors and sensors.
At Gnee Alloy, we offer premium GH4169 (equivalent to Inconel 718) seamless steel tubing. Our tubing is meticulously designed for exceptional structural integrity, capable of withstanding extreme environments that other products cannot withstand.
Contact our professionals to recommend the right alloy for your project
Heat-resistant GH4169 (Inconel 718) high-pressure aerospace seamless tubing
Heat-resistant GH4169 (Inconel 718) high-pressure aerospace seamless tubing
GH4169 (Inconel 718) is a high-quality nickel-based superalloy designed for extreme environments and widely used in high-pressure seamless steel tubing in the aerospace industry. It features high tensile strength, excellent creep rupture strength at temperatures up to 700°C (1300°F), and outstanding corrosion/oxidation resistance.
What is GH4169?
GH4169 alloy is a precipitation strengthened nickel base superalloy, which has been widely used in aeroengine, petroleum, nuclear industry and other fields. The phase composition, three common heat treatments as well as the application prospect were elaborated.
1. Performance and Standards of Heat-Resistant GH4169 High-Pressure Seamless Aerospace Steel Pipe
| Parameter | Specification Detail | Industrial Advantage |
| Material Grade | GH4169 / Inconel 718 / UNS N07718 | Direct Global Compatibility. |
| Standard | AMS 5589, AMS 5590, ASTM B637 | Certified for High-Pressure Service. |
| Yield Strength | ≥ 850 MPa at 650°C | Prevents deformation under load. |
| Tolerance | h8, h9, h10 Precision | Perfect fit for hydraulic fittings. |
| Inspection | 100% UT & Eddy Current | Guaranteed Zero Defect quality. |
3. Aerospace-grade AMS 5589/5590 heat-resistant GH4169 seamless steel pipe, chemical composition (weight %)
| Element | Content (%) | Standard Requirement | Function |
|---|---|---|---|
| Nickel (Ni) | 50.0 – 55.0 | 50.0 – 55.0 | Matrix element; provides high-temperature stability and corrosion resistance |
| Chromium (Cr) | 17.0 – 21.0 | 17.0 – 21.0 | Oxidation and corrosion resistance |
| Iron (Fe) | Balance (~18-20) | Balance | Fe-Ni-Cr base alloy |
| Niobium (Nb) | 4.75 – 5.50 | 4.75 – 5.50 | Core strengthening element – forms γ″ phase (Ni₃Nb) for high temperature strength |
| Molybdenum (Mo) | 2.80 – 3.30 | 2.80 – 3.30 | Solid-solution strengthening; enhances creep and pitting resistance |
| Titanium (Ti) | 0.65 – 1.15 | 0.65 – 1.15 | Forms γ′ strengthening phase (Ni₃(Al,Ti)) |
| Aluminum (Al) | 0.20 – 0.80 | 0.20 – 0.80 | Forms γ′ strengthening phase; improves oxidation resistance |
| Carbon (C) | ≤ 0.08 | ≤ 0.08 | Low carbon for weldability and toughness |
| Manganese (Mn) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Silicon (Si) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Phosphorus (P) | ≤ 0.010 | ≤ 0.015 (AMS stricter) | Ensures toughness |
| Sulfur (S) | ≤ 0.005 | ≤ 0.015 (AMS stricter) | Ensures hot workability |
| Boron (B) | 0.002 – 0.006 | 0.002 – 0.006 | Grain boundary strengthener; improves stress rupture life |
| Cobalt (Co) | ≤ 1.00 | ≤ 1.00 | Residual element |
| Copper (Cu) | ≤ 0.30 | ≤ 0.30 | Residual element |
Click to download the GH4169 alloy PDF file now
3. Dimensions of heat-resistant GH4169 high-pressure seamless aerospace steel pipe
| OD (mm) | OD (in) | Wall (mm) | Wall (in) | Working Pressure (psi) | Typical Application |
|---|---|---|---|---|---|
| 3.18 | 0.125 | 0.51 | 0.020 | 8,500 | Instrumentation lines |
| 4.76 | 0.188 | 0.71 | 0.028 | 9,500 | Control lines |
| 6.35 | 0.250 | 0.89 | 0.035 | 11,000 | Fuel lines |
| 6.35 | 0.250 | 1.24 | 0.049 | 16,000 | High pressure fuel |
| 9.53 | 0.375 | 1.07 | 0.042 | 12,500 | Bleed air ducts |
| 9.53 | 0.375 | 1.65 | 0.065 | 20,000 | High pressure bleed air |
| 12.70 | 0.500 | 1.24 | 0.049 | 13,500 | High pressure hydraulic |
| 12.70 | 0.500 | 1.65 | 0.065 | 18,500 | Main hydraulic lines |
| 15.88 | 0.625 | 1.65 | 0.065 | 15,000 | Turbine cooling |
| 15.88 | 0.625 | 2.11 | 0.083 | 20,000 | High pressure cooling |
4. Heat-resistant GH4169 seamless steel pipe - Room temperature and mechanical properties
Condition: Solution Treated + Aged (Hard – Recommended for High Pressure Service)
| Property | AMS 5589/5590 Requirement | Typical Value | Test Standard |
|---|---|---|---|
| Tensile Strength, Ultimate (Rm) | ≥ 1275 MPa (185 ksi) | ~1350 MPa | ASTM E8 / AMS 2370 |
| Tensile Strength, Yield (Rp0.2) | ≥ 1035 MPa (150 ksi) | ~1100 MPa | ASTM E8 / AMS 2370 |
| Elongation at Break (A) | ≥ 12% | ~15-20% | ASTM E8 / AMS 2370 |
| Reduction of Area (Z) | ≥ 15% | ~20-25% | ASTM E8 |
| Hardness (Rockwell C) | 35 – 40 HRC | ~38 HRC | ASTM E18 |
| Modulus of Elasticity (E) | ~200 GPa | – | ASTM E111 |
| Poisson's Ratio (ν) | 0.29 – 0.30 | – | – |
Condition: Solution Treated (Soft – for Tube Bending)
| Property | Requirement | Typical Value |
|---|---|---|
| Tensile Strength, Ultimate | ≥ 965 MPa (140 ksi) | ~1000 MPa |
| Tensile Strength, Yield | ≥ 550 MPa (80 ksi) | ~600 MPa |
| Elongation at Break | ≥ 30% | ~35-40% |
| Hardness | ≤ 24 HRC | ~20-22 HRC |
5. Non-destructive testing (NDT) requirements for GH4169 high-pressure aerospace tubes
| Test Method | Aerospace Requirement | Standard | Acceptance Criteria |
|---|---|---|---|
| Eddy Current Testing (ET) | 100% | ASTM E426 | No relevant indications |
| Ultrasonic Testing (UT) | 100% (wall ≥ 0.5mm) | ASTM E213 | No defects exceeding 5% wall |
| Hydrostatic Test | 100% | ASME Section VIII | 1.5× working pressure, no leakage |
| Helium Leak Test | As specified | ASTM E498 | ≤ 1 × 10⁻⁹ std cc/sec |
| Borescope Inspection | 100% | – | Smooth, clean ID, no defects |
| Visual Inspection | 100% (10-30x magnification) | ASTM E543 | No surface defects |
6. GH4169 Aircraft Pipeline Application
As a Reliable Supplier, we provide certified GH4169 tubing for:
Common-Rail Fuel Injection: Handling 2000+ bar pressure at elevated temperatures.
Aerospace Hydraulic Lines: High-vibration flight control systems.
Nuclear Reactor Instrumentation: High-strength structural conduit.
Petrochemical Reactors: Transporting hot, high-pressure corrosive media.
Why choose Tier 1 manufacturer Gnee Alloy?
✅️Direct Factory Price: Eliminate middleman markups and secure the best rates for bulk procurement.
✅️MTC 3.1 Traceability: Full heat analysis and hydrostatic test reports included with every shipment.
✅️Wholesale Inventory: We maintain a large stock of standard ANSI schedules (Sch 40, Sch 80) and capillary sizes for Fast Global Shipping.
✅️Custom Fabrication: We offer precision cutting, centerless grinding, and specialized end-forming to match your blueprints.
Gnee Steel GH4169 Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Steel GH4169 Product Packing
Contact us for the latest export price quote for GH4169 Alloy
FAQ
Q1: Is GH4169 tubing safe for liquid hydrogen transport?
A: Yes. GH4169 maintains exceptional toughness and ductility down to -253°C, making it the premier choice for cryogenic high-pressure fuel lines in space exploration.
Q2: How do you guarantee the burst pressure rating of your tubes?
A: We perform 100% Hydrostatic Pressure Testing and Eddy Current testing. We can provide the specific burst pressure calculation for your required OD/WT according to ASME B31.3.
Q3: Is there a difference between AMS 5589 and AMS 5590 tubing?
A: AMS 5589 is typically for seamless tubing in the solution-treated condition (pickled), while AMS 5590 is usually for bright-annealed tubing. We offer both depending on your surface cleanliness requirements.
Q4: Do you offer bulk discounts for aerospace maintenance (MRO) projects?
A: Yes. As a Tier-1 Supplier, we support long-term MRO contracts with attractive Wholesale Pricing and priority inventory reserves.
