---
title: "Hydraulic Gap Control"
industry: "Basic Metal Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:HYDRAULIC_GAP_CONTROL"
  data_integrity_hash: "9288e3153097d62369b0cf91979f4394"
  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:HYDRAULIC_GAP_CONTROL"
  data_source_uri: "https://cnfx.com/llms/industry/basic-metal-manufacturing/product/hydraulic-gap-control.md"
  official_resource_url: "https://cnfx.com/industry/basic-metal-manufacturing/product/hydraulic-gap-control"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "15-300 bar hydraulic pressure, 0.01-0.5 mm gap control accuracy, 20-80°C operating temperature"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 350
    unit: "bar"
    consequence: "Seal failure occurs at 350 bar due to elastomer tensile strength limit (35 MPa for HNBR), gap control failure at ±0.75 mm deviation due to material yield strength exceedance, thermal failure at 90°C due to hydraulic fluid viscosity dropping below 10 cSt causing loss of laminar flow"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Hydraulic fluid contamination exceeding ISO 4406 18/16/13 cleanliness level"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Install dual 3 μm absolute filtration with pressure differential monitoring and automatic bypass"
  - node_2:
      trigger: "Position transducer thermal drift exceeding 0.05% FS/°C specification"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Implement dual-redundant LVDT position feedback with temperature compensation algorithm using PT100 sensors"
bom_nodes:
  hydraulic-cylinder:
    type: "part"
    urn: "URN:CNFX:ME:HYDRAULIC_CYLINDER"
    interface_type: "physical-logic-coupled"
  servo-valve:
    type: "part"
    urn: "URN:CNFX:ME:SERVO_VALVE"
    interface_type: "physical-logic-coupled"
  position-sensor:
    type: "part"
    urn: "URN:CNFX:ME:POSITION_SENSOR"
    interface_type: "physical-logic-coupled"
  control-unit:
    type: "part"
    urn: "URN:CNFX:ME:CONTROL_UNIT"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
url: "https://cnfx.com/llms/industry/basic-metal-manufacturing/product/hydraulic-gap-control.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "b97e6fca86184a9882cbea844d61d5df32a7b0d53c6d0e5676c4694717e7b9bd"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Hydraulic Gap Control

## 1. Technical Definition
A hydraulic system that precisely controls the gap between work rolls in a rolling mill to achieve desired material thickness and quality.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **15-300 bar hydraulic pressure, 0.01-0.5 mm gap control accuracy, 20-80°C operating temperature**. Failure boundary: **Hydraulic pressure exceeds 350 bar causing seal rupture, gap deviation exceeds ±0.75 mm causing material quality failure, temperature exceeds 90°C causing fluid degradation**, Mechanism: **Seal failure occurs at 350 bar due to elastomer tensile strength limit (35 MPa for HNBR), gap control failure at ±0.75 mm deviation due to material yield strength exceedance, thermal failure at 90°C due to hydraulic fluid viscosity dropping below 10 cSt causing loss of laminar flow**.

### 2.1 Analytical Physics Model
Governed by the **Darcy-Weisbach Pressure Drop**:

> **Primary Equation**: $\Delta P = f \cdot \frac{L}{D} \cdot \frac{\rho v^2}{2}$  
> **Engineering Impact**: Critical for sizing CIP (Clean-In-Place) pump heads.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| f | Friction Factor | Engineering Constant |
| L | Pipe Length | Engineering Constant |
| v | Velocity | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Hydraulic fluid contamination exceeding ISO 4406 18/16/13 cleanliness level | 8 | Servo valve spool sticking causing 0.3-0.8 mm gap oscillation | Install dual 3 μm absolute filtration with pressure differential monitoring and automatic bypass |
| Position transducer thermal drift exceeding 0.05% FS/°C specification | 8 | Gap control error accumulating to 0.4 mm over 8-hour production run | Implement dual-redundant LVDT position feedback with temperature compensation algorithm using PT100 sensors |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Hydraulic Cylinder](https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/hydraulic-cylinder.md) `(Standalone System)`
- [Servo Valve](https://cnfx.com/llms/industry/basic-metal-manufacturing/product/servo-valve.md) `(Standalone System)`
- [Position Sensor](https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/position-sensor.md) `(Standalone System)`
- [Control Unit](https://cnfx.com/llms/industry/machinery-and-equipment-manufacturing/product/control-unit.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Hydraulic Power Unit**, **Cooling System**, **Roll Grinding Machine**  
**Downstream Applications**: Steel Sheets, Aluminum Coils, Brass Strips  

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

### Q: How does hydraulic gap control improve material quality in rolling mills?
**A**: Hydraulic gap control maintains precise, consistent spacing between work rolls through servo valves and position sensors, ensuring uniform material thickness, reducing defects, and improving surface finish in metal products.

### Q: What maintenance is required for hydraulic gap control systems?
**A**: Regular maintenance includes monitoring hydraulic seals for leaks, calibrating position sensors, checking servo valve performance, and inspecting high-strength alloy steel components for wear to ensure continuous precision operation.

### Q: Can hydraulic gap control systems be retrofitted to existing rolling mills?
**A**: Yes, hydraulic gap control systems can be integrated with existing rolling mills by installing hydraulic cylinders, servo valves, position sensors, and a control unit, often improving thickness accuracy without complete mill replacement.

## 6. Manufacturing Compliance

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Hydraulic Gap Control](https://cnfx.com/industry/basic-metal-manufacturing/product/hydraulic-gap-control)**

### 🌐 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**: HYDRAULIC_GAP_CONTROL | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: a7bea599
