---
title: "Common Rail"
industry: "Motor Vehicle Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:COMMON_RAIL"
  data_integrity_hash: "fc8a2460d14b4801b97defee33b5b802"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:COMMON_RAIL"
  data_source_uri: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/common-rail.md"
  official_resource_url: "https://cnfx.com/industry/motor-vehicle-manufacturing/product/common-rail"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "200-2500 bar"
    unit: "bar"
engineering_limits:
  max_safe_operating_point:
    value: 2800
    unit: "bar"
    consequence: "High-cycle fatigue from pressure pulsations at 1-10 Hz, combined with hydrogen embrittlement from diesel fuel at 150°C operating temperature"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Fuel contamination with 5-15 μm abrasive particles exceeding ISO 4406 18/16/13 cleanliness code"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Installation of 3 μm absolute filtration with differential pressure monitoring at 0.5 bar threshold"
  - node_2:
      trigger: "Thermal cycling between -40°C and 150°C at 2 cycles/hour"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Post-weld heat treatment at 620°C for 2 hours followed by 100% phased array ultrasonic testing"
bom_nodes:
  rail-pipe:
    type: "part"
    urn: "URN:CNFX:ME:RAIL_PIPE"
    interface_type: "physical-logic-coupled"
  pressure-sensor-port:
    type: "component"
    urn: "URN:CNFX:ME:PRESSURE_SENSOR_PORT"
    interface_type: "physical-logic-coupled"
  injector-connections:
    type: "component"
    urn: "URN:CNFX:ME:INJECTOR_CONNECTIONS"
    interface_type: "physical-logic-coupled"
  pressure-limiter-valve:
    type: "part"
    urn: "URN:CNFX:ME:PRESSURE_LIMITER_VALVE"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 7870-1:2019 (STATISTICAL PROCESS CONTROL)"
    scope: "Verified Engineering Specification"
  - standard: "DIN EN 13813:2003 (MATERIALS AND COMPONENTS FOR PRESSURE EQUIPMENT)"
    scope: "Verified Engineering Specification"
  - standard: "CE MARKING (PRESSURE EQUIPMENT DIRECTIVE 2014/68/EU)"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/common-rail.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "9c46f2f8556dd9260ec745069a9e97793caa7e7dcf8f15cc40e64b183b429ae1"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Common Rail

## 1. Technical Definition
A high-pressure fuel distribution pipe that supplies pressurized diesel to individual fuel injectors in modern diesel engines.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **200-2500 bar**. Failure boundary: **2800 bar (yield strength of SAE 4130 steel at 150°C)**, Mechanism: **High-cycle fatigue from pressure pulsations at 1-10 Hz, combined with hydrogen embrittlement from diesel fuel at 150°C operating temperature**.

### 2.1 Analytical Physics Model
Governed by the **Thin-Wall Pressure Vessel Stress Analysis**:

> **Primary Equation**: $\sigma_h = \frac{P \cdot D}{2t}$  
> **Engineering Impact**: Determines the hoop stress boundary to prevent rupture.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| P | Internal Pressure | Engineering Constant |
| D | Diameter | Engineering Constant |
| t | Wall Thickness | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Fuel contamination with 5-15 μm abrasive particles exceeding ISO 4406 18/16/13 cleanliness code | 8 | Injector nozzle erosion causing 15% flow deviation from nominal 200 cm³/min at 1000 bar | Installation of 3 μm absolute filtration with differential pressure monitoring at 0.5 bar threshold |
| Thermal cycling between -40°C and 150°C at 2 cycles/hour | 8 | Microcrack propagation in welded joints exceeding 0.1 mm critical flaw size per ASME BPVC Section VIII | Post-weld heat treatment at 620°C for 2 hours followed by 100% phased array ultrasonic testing |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | bar | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Rail Pipe](https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/rail-pipe.md) `(Standalone System)`
- [Pressure Limiter Valve](https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/pressure-limiter-valve.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **High-Pressure Fuel Pump**, **Electronic Control Unit (ECU)**, **Fuel Injector Tester**  
**Downstream Applications**: Diesel Engine Assembly, Commercial Vehicle, Agricultural Machinery  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What materials are used in manufacturing common rail systems?
**A**: Common rail systems are typically constructed from high-strength steel or stainless steel to withstand extreme pressures and resist corrosion in diesel engine environments.

### Q: How does the pressure limiter valve function in a common rail?
**A**: The pressure limiter valve maintains optimal fuel pressure within the rail by releasing excess pressure when it exceeds predetermined safety levels, ensuring consistent injector performance and preventing system damage.

### Q: What are the key components of a common rail assembly?
**A**: A complete common rail assembly includes the main rail pipe, pressure sensor port for monitoring, multiple injector connections for fuel distribution, and a pressure limiter valve for system protection.

## 6. Manufacturing Compliance
- ISO 7870-1:2019 (STATISTICAL PROCESS CONTROL)
- DIN EN 13813:2003 (MATERIALS AND COMPONENTS FOR PRESSURE EQUIPMENT)
- CE MARKING (PRESSURE EQUIPMENT DIRECTIVE 2014/68/EU)

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Common Rail](https://cnfx.com/industry/motor-vehicle-manufacturing/product/common-rail)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: COMMON_RAIL | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: f90cc794
