Details

1. Introduction
The Test Rig for OBIGGS is a turnkey ground-station platform built to execute exhaustive qualification, acceptance testing and R&D for On-Board Inert Gas Generating Systems (OBIGGS) destined for military and transport aircraft. By precisely reproducing bleed-air conditions (pressure, temperature, humidity and dynamic transients), this rig validates every critical performance metric—membrane integrity, inert-gas purity, response times and leak tightness—ensuring systems meet or exceed industry and regulatory mandates.

Core Deliverables:
• Fully sequenced, PLC-driven test profiles with customizable parameters
• High-speed data capture (1 Hz–10 Hz) of pressure, flow, temperature and gas composition
• Auto-generated certification-ready reports and raw data export (CSV/PDF/XML)
• Turnkey installation, operator training and maintenance support

2. OBIGGS: Purpose & Application
2.1. Why Fuel-Tank Inerting?
Fuel-tank ullage—filled with a fuel–air mixture—becomes explosive if the oxygen fraction exceeds~12 % by volume. Ignition sources include: lightning strikes, static discharge, combat damage and high-energy sparking. Inerting displaces oxygen, breaking the combustion triangle (fuel + oxidizer + ignition), thus preventing catastrophic tank explosions.

2.2. OBIGGS Operation
1. Bleed-Air Extraction: Air tapped from engine compressor section (200–300 °C, 4–7 bar).
2. Air Pre-Treatment: Multi-stage filtration and heat-exchangers remove particulates, oil carryover and moisture to ISO 8573-1 Class 1.1.1.
3. Membrane Separation: Hollow-fiber membrane bundles selectively permeate O₂ and H₂O; retained nitrogen-enriched air (NEA) achieves ≥ 90 % N₂ purity.
4. Ullage Inerting: NEA is delivered continuously to the fuel-tank ullage, maintaining O₂ ≤ 10–12 %.
5. Permeate Management: O₂-rich exhaust vents overboard or recycles to low-pressure return.

2.3. Benefits & Use Cases
• Survivability: Prevents explosion under battle damage or lightning.
• Regulatory Compliance: Meets FAA/EASA fuel-tank safety rules; MIL-STD-810G and SAE AS82137.
• Weight & Volume Savings: No heavy gas bottles—membrane modules are compact and light.
• Continuous Protection: Inerting maintained throughout all flight phases.
• Low Lifecycle Cost: Minimal moving parts; membrane life > 5 000 hr with simple filter changes.

Deployments: F-16, Rafale, Eurofighter, A-330 MRTT, KC-135, military helicopters, UAVs.

3. System Architecture
3.1Air Supply & Regulation
  - 8 bar(g) @ 1 000 LPM NTP primary inlet, ISO 8573-1 filtration
  - PR-1 (0.5–12 bar, 3 500 LPM) and PR-2 (0.5–7 bar, 1 600 LPM) precision regulators
  - Four bi-stable ball valves (–0.95 → +30 bar, 15 mm port) for isolation

3.2 Flow Control & Measurement
  - Manual needle valves for sweep-rate profiling (1–10 bar)
  - Mass flow meters:
    ▪ FM-1: 0–100 LPM (±2 % F.S.)
    ▪ FM-2: 50–500 LPM (±2 % F.S.)
    ▪ FM-3/4: 94–944 ccm (±2 % F.S.) for low-flow

3.3 Oxygen Analysis
  - Servomex MiniMP 5200 paramagnetic analyzer
  - 0–100 % O₂ range, ±0.02 % accuracy, T₉₀ < 15 s
  - Automated zero/span calibration; on-board pressure/temperature compensation

3.4 Control & Data Acquisition
  - Siemens S7-1200 PLC with analog/digital I/O
  - 10.1″ HMI touchscreen for real-time control and trending
  - Windows 10 laptop with custom SCADA: test scripting, live charts, CSV/PDF/XML export

4. Technical Specifications

  

    

      
Category
      
Specification
    
  
  

    

      
Pneumatics
      
Inlet: 8 bar(g) @ 1 000 LPM NTP
Filtration: ISO 8573-1 Class 1.1.1
PR-1: 0.5–12 bar, 3 500 LPM
PR-2: 0.5–7 bar, 1 600 LPM
    
    

      
Valves & Fittings
      
On/Off Valves: 4× 15 mm bi-stable ball valves (–0.95→+30 bar)
Needle Valves: 2× 1–10 bar adjustment
Push-in fittings, 8 mm/12 mm tubing
    
    

      
Flow Measurement
      
FM-1: 0–100 LPM ±2 % F.S.
FM-2: 50–500 LPM ±2 % F.S.
FM-3/4: 94–944 ccm ±2 % F.S.
    
    

      
Gas Analysis
      
Analyzer: Servomex MiniMP 5200 (paramagnetic)
Range: 0–100 % O2
Accuracy: ±0.02 % O2
T90: < 15 s
    
    

      
Control System
      
PLC: Siemens S7-1200
HMI: 10.1″ TFT touchscreen
Software: Custom SCADA (test sequencing, data export)
    
    

      
Data Logging
      
Sampling Rate: 1–10 Hz
Storage: Local SSD; USB backup
Export: CSV, PDF, XML
    
    

      
Electrical
      
Supply: 230 VAC ±10 %, 50 Hz, 2 kW
Protection: RCD, MCBs, E-stop
EMC: Complies with EN 55011, EN 61326
    
    

      
Mechanical
      
Frame: Powder-coated 304 SS
Dimensions: 1 200×800×1 600 mm (L×W×H)
Weight: ~320 kg
Mobility: Lockable castors
    
    

      
Environmental
      
Operating: +10 °C to +50 °C (optional chamber: –20 °C to +60 °C)
Humidity: 10–90 % RH non-condensing
    
    

      
Safety Features
      
E-stop, over-pressure relief valves @ 16 bar, safety interlocks
Leak-down alarm
    
    

      
Compliance
      
CE (EMC, LVD), MIL-STD-810G (shock/vibration/temperature), ISO 9001:2015
    
    

      
Documentation
      
IQ/OQ/PQ protocols, FAT/SAT templates, calibration certificates
    
    

      
Training & Support
      
2-day on-site training; 12-month warranty (extendable to 36 months); annual maintenance contracts available
    
  


5. Mechanical & Environmental Design
• Chassis & Enclosure: Corrosion-resistant 304 SS, powder-coated, tamper-proof panels with quick-release latches.
• Mobility: Heavy-duty swivel castors with integrated brakes.
• Thermal Management: Forced-air ventilation for electronics; optional temperature chamber for environmental stress testing (–20 °C to +60 °C).
• Service Access: Color-coded pneumatics, clearly labeled ports, removable panels for rapid maintenance and calibration.

6. Operational Workflow
1. Setup & Calibration
  - Connect single-point pneumatic and 230 VAC power.
  - Run automated analyzer zero/span and system leak-down check (hold at 10 bar for 5min).

2. Test Sequencing
  - Define profiles: pressure ramps (0.5 bar steps), flow sweeps (50→500 LPM), temperature cycles.
  - Initiate via HMI or SCADA; PLC executes valve actuation and data capture.

3. Real-Time Monitoring
  - Live trending of key parameters: P_in, ΔP across membrane, flow, O₂%.
  - Alarm thresholds for over-pressure, O₂ deviation, leaks.

4. Reporting & Analysis
  - Auto-generate certification reports: plots, tables, pass/fail summaries.
  - Export raw data for custom analysis (MATLAB, Python, etc.).

7. Safety, Compliance & Quality
• Safety Interlocks: Emergency-stop cuts all power and pneumatic lines; over-pressure relief valves at 16 bar; leak alarm with auto-shutdown.
• Regulatory Compliance: CE marking (EMC/LVD), MIL-STD-810G shock/vibration/temperature, ISO 9001:2015 quality assurance.
• Documentation Package: First-Article Inspection (FAI) with traceable calibration certificates; IQ/OQ/PQ protocols; FAT/SAT execution templates; full user and maintenance manuals.

8. Installation, Training & After-Sales
• Installation: Single-point hookups; onsite commissioning by factory engineers; FAT demonstration.
• Training: Two days of hands-on operator and maintenance training covering system operation, calibration, troubleshooting and safety procedures.
• Support:
  - Warranty: Standard 12 months (extendable to 36 months).
  - Maintenance Contracts: Annual calibration, software updates and priority spareparts provisioning.
  - Remote Assistance: Secure VPN access for diagnostics and software support.

The Test Rig for OBIGGS equips aerospace OEMs, MRO depots and R&D centers with an uncompromising, end-to-end solution for validating and certifying inert-gas generating systems. Its robust design, exhaustive automation and turnkey support minimize commissioning time and
operational risk—delivering peace of mind and compliance in the most demanding flight-safety applications.