---
title: "Manhole/Access Hatch"
industry: "Fabricated Metal Product Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:MANHOLEACCESS_HATCH"
  data_integrity_hash: "37a5e7f5656dad0bfef8e17374a9f0df"
  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:MANHOLEACCESS_HATCH"
  data_source_uri: "https://cnfx.com/llms/industry/fabricated-metal-product-manufacturing/product/manholeaccess-hatch.md"
  official_resource_url: "https://cnfx.com/industry/fabricated-metal-product-manufacturing/product/manholeaccess-hatch"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-0.5 bar differential pressure"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 1.2
    unit: "bar"
    consequence: "Plastic deformation due to exceeding yield strength of 275 MPa in ASTM A36 steel at 0.2% offset"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Corrosion-induced material thinning below 4mm thickness"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "316L stainless steel construction with 6mm minimum thickness and cathodic protection"
  - node_2:
      trigger: "Fatigue cracking from 10^5+ cyclic pressure fluctuations between 0-0.3 bar"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Elliptical design with 3:1 major:minor axis ratio and shot peening to induce 400 MPa compressive residual stress"
bom_nodes:
  hatch-cover:
    type: "component"
    urn: "URN:CNFX:ME:HATCH_COVER"
    interface_type: "physical-logic-coupled"
  gasketseal:
    type: "component"
    urn: "URN:CNFX:ME:GASKETSEAL"
    interface_type: "physical-logic-coupled"
  hingesbolts:
    type: "component"
    urn: "URN:CNFX:ME:HINGESBOLTS"
    interface_type: "physical-logic-coupled"
  safety-lock:
    type: "component"
    urn: "URN:CNFX:ME:SAFETY_LOCK"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 - QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/fabricated-metal-product-manufacturing/product/manholeaccess-hatch.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "38dccb63d98cef5a7b9cfdc29e05e9f83f07724c6f6dee407f418f1854b0d2bd"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Manhole/Access Hatch

## 1. Technical Definition
A removable cover or door that provides access to the interior of a recovery tank for inspection, maintenance, and cleaning purposes.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-0.5 bar differential pressure**. Failure boundary: **1.2 bar differential pressure causing permanent deformation exceeding 3mm**, Mechanism: **Plastic deformation due to exceeding yield strength of 275 MPa in ASTM A36 steel at 0.2% offset**.

### 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 |
| :--- | :--- | :--- | :--- |
| Corrosion-induced material thinning below 4mm thickness | 8 | Structural collapse under 0.8 bar differential pressure | 316L stainless steel construction with 6mm minimum thickness and cathodic protection |
| Fatigue cracking from 10^5+ cyclic pressure fluctuations between 0-0.3 bar | 8 | Through-thickness fracture propagation at 15mm crack length | Elliptical design with 3:1 major:minor axis ratio and shot peening to induce 400 MPa compressive residual stress |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **CNC Plasma Cutting Machine**, **Hydraulic Press Brake**, **MIG Welding System**  
**Downstream Applications**: Industrial Recovery Tanks, Wastewater Treatment Systems, Chemical Storage Vessels  

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

### Q: What materials are available for the manhole/access hatch?
**A**: Our hatches are fabricated in stainless steel, carbon steel, and aluminum to suit different industrial environments and corrosion resistance needs.

### Q: What components are included in the hatch assembly?
**A**: Each hatch includes a cover, gasket/seal, hinges or bolts for mounting, and a safety lock to secure access points.

### Q: What are the primary applications for this access hatch?
**A**: It provides secure access to recovery tanks for inspection, routine maintenance, and thorough cleaning operations in industrial settings.

## 6. Manufacturing Compliance
- ISO 9001:2015 - QUALITY MANAGEMENT SYSTEMS

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Manhole/Access Hatch](https://cnfx.com/industry/fabricated-metal-product-manufacturing/product/manholeaccess-hatch)**

### 🌐 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**: MANHOLEACCESS_HATCH | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 68dee127
