ATEX Modernization in Existing Facilities: A Guide to Operational Safety and Efficiency

1. Introduction: The Imperative Need for ATEX Modernization

Safety in industrial environments with potentially explosive atmospheres (ATEX) is non-negotiable. European directives, such as Directive 2014/34/EU (ATEX), establish strict requirements for equipment and protective systems intended for use in such areas. However, many manufacturing facilities in Spain and Latin America operate with legacy equipment that, while compliant with previous regulations, may not meet current safety and efficiency standards. Modernization is not only a legal obligation in many cases, but a critical investment to reduce risks, optimize performance and ensure operational continuity. Technological obsolescence not only implies a greater risk of failure, but also lower energy efficiency and an increase in maintenance costs, which directly impacts profitability.

This white paper addresses system rehabilitation in ATEX classified environments, providing a roadmap for plant engineers, maintenance managers and Capex decision makers. A pragmatic analysis of the tangible benefits of investing in technology in accordance with the latest standards is presented.

2. Evaluation of the Legacy System: Essential Criteria Before Retrofit

Before undertaking any modernization project, it is essential to conduct a thorough assessment of existing systems. This assessment not only identifies deficiencies in relation to current ATEX regulations, but also quantifies the cost associated with inefficiency and risk. Resistance to modernization, often based on the premise that “the old system still works,” ignores Total Cost of Ownership (TCO) and latent risks.

Table 2.1: Evaluation Criteria for Legacy ATEX Systems

3. Modern Alternatives: Advanced ATEX Technology

Technology has evolved, offering safer, more efficient and reliable solutions for ATEX environments. Replacing critical components with modern, certified equivalents can transform an outdated system. An example of effective modernization is the replacement of conventional bearing units with integrated and sealed solutions, specifically designed for explosive atmospheres.

Modern Component Example: SKF VPKG-3-03041

The SKF VPKG-3-03041 bearing unit represents a robust solution for applications with ATEX requirements. This type of unit, designed to operate in classified areas, offers a combination of intrinsic safety and efficiency.

Table 3.1: Comparison: Old Technology vs. Modern ATEX (Bearing Unit Example)

4. Calculation of Return on Investment (ROI) in ATEX Modernization

The economic argument for ATEX modernization is compelling. The initial investment is quickly offset by operational savings, risk reduction and increased productivity. Let's consider a practical case in a grain processing plant, where ATEX Zone 21 is required, and the replacement of 10 obsolete bearing units with SKF VPKG-3-03041.

4.1. Base Scenario (Old System)

• Downtime Cost for Bearing Failure: €5,000 per hour of lost production (includes labor, material, impact on the program).
• Failure Frequency: 1 major failure per 10 bearings per year.
• Fault Repair Time: 8 hours.
• Annual Preventive Maintenance Cost per Bearing: €150 (lubrication, inspections).
• Energy Cost per Bearing (extra friction): Additional consumption of 0.5 kW/bearing * 8,000 hours/year * €0.15/kWh = €600/bearing/year.
• Total Annual Cost for Failures and Maintenance of Old Bearings (10 units):
  • Downtime: 1 failure/year * 8 hours/failure * €5,000/hour = €40,000
  • Preventive Maintenance: 10 * €150 = €1,500
  • Energy: 10 * €600 = €6,000
  • Total: €47,500 per year.

4.2. Modernized Scenario (SKF VPKG-3-03041)

• Initial Investment: 10 units SKF VPKG-3-03041 * €800/unit = €8,000 (estimated cost of the component, excludes installation).
• Reduction in Failures: Modern ATEX bearings have proven reliability. We assume a 90% reduction in major failures, which means 0.1 failures/year.
• Downtime Cost per Failure (reduced): 0.1 failures/year * 8 hours/failure * €5,000/hour = €4,000.
• Preventive Maintenance Reduction: Relubrication frequency is drastically reduced or eliminated. We assume 75% savings. Annual Preventive Maintenance Cost per Bearing: €150 * 0.25 = €37.5.
• Energy Savings: 25% reduction in energy consumption due to less friction. Savings of 0.125 kW/bearing * 8,000 hours/year * €0.15/kWh = €150/bearing/year.
• Total Annual Cost of Modern Bearings (10 units):
  • Downtime: €4,000
  • Preventive Maintenance: 10 * €37.5 = €375
  • Energy: 10 * (€600 - €150) = €4,500
  • Total: €8,875 per year.

4.3. ROI calculation

• Total Annual Savings: €47,500 (old) - €8,875 (modern) = €38,625.
• Payback Period: €8,000 (initial investment) / €38,625 (annual savings) ≈ 0.21 years, or approximately 2.5 months.

This simplified calculation demonstrates that the return on investment for ATEX retrofitting, especially on critical and energy-intensive components, can be extraordinarily fast. Energy efficiency regulations, such as those promoted by the Energy Efficiency Directive 2012/27/EU (transposed in Spain), actively encourage these investments.

5. Implementation Roadmap: Minimizing Disruption

Modernization in an active plant must be meticulously planned to minimize production downtime.

5.1. Implementation Phases

1. Planning and Audit (Weeks 1-4):
   • Detailed audit of the installation, identification of equipment and ATEX zones.
   • Risk assessment and compliance with UNE-EN 60079 and 1127-1.
   • Selection of certified ATEX components (e.g. SKF VPKG-3-03041 units) and suppliers.
   • Development of a detailed project plan, including cost and benefit analysis (Capex vs. Opex).
   • Preparation of security and permit documentation.
2. Engineering and Design (Weeks 5-8):
   • Design of the integration of new components.
   • Specification of materials, wiring, enclosures and protection systems (e.g. intrinsic safety barriers).
   • Preparation of installation plans and work procedures.
   • Training of maintenance and installation personnel.
3. Acquisition and Preparation (Weeks 9-12):
   • Acquisition of all ATEX components and equipment, including spare parts. UNITEC-D offers a wide catalog of components to guarantee availability.
   • Pre-assembly and testing of individual components offline if possible.
   • Logistics and secure storage.
4. Installation and Configuration (Weeks 13-16, during scheduled shutdowns):
   • Safe disconnection of old equipment.
   • Installation of new components following safe work procedures and ATEX standards.
   • Electrical connection, instrumentation and initial start-up.
   • Minimize interruption by scheduling maintenance windows or plant shutdowns.
5. Commissioning and Verification (Weeks 17-18):
   • Operational tests, verification of operating parameters and safety.
   • Final certification and issuance of ATEX Declarations of Conformity.
   • Update of technical and maintenance documentation.

6. Common Technical Challenges and Solutions

Modernizing brownfield facilities presents unique challenges. Rigorous planning and execution are key.

• Integration with Existing Infrastructure: New components must be compatible with existing physical space and control interfaces. Solution: Carry out a detailed survey and, if necessary, use adapters or design custom interfaces.
• ATEX Zone Management: The zone classification may have changed or be more restrictive. Solution: Re-evaluate the zone classification according to UNE-EN 60079-10-1 and UNE-EN 60079-10-2, and select equipment with the appropriate ATEX equipment category.
• Dust and Flammable Gas Control: During installation, the disturbance may release dust or gases. Solution: Implement hot and cold work procedures, forced ventilation, continuous atmosphere monitoring and ATEX work permits.
• Staff Training: Staff must be trained in the handling and maintenance of the new ATEX equipment. Solution: Specific training programs on the use, inspection and maintenance of the installed technology.
• Obtaining Certifications: Ensure that all equipment and the final installation comply with the ATEX 2014/34/EU Directive. Solution: Collaborate with notified bodies and certified suppliers.

7. Case Study: Modernization of a Grain Conveyor in a Feed Factory

Previous Situation: A feed factory operated with a screw conveyor in an area classified as ATEX Zone 21 (combustible dust). The 8 conveyor bearings were open units with periodic greasing. They had an MTBF of 18,000 hours, with two major failures per year that caused an average interruption of 12 hours each. The energy cost due to friction was high, and there was a constant risk of ignition due to overheating or sparks due to friction.

Modernization Objective: Improve ATEX safety, reduce downtime, reduce maintenance and energy costs, and extend the useful life of the bearings.

Implemented Solution: Replacement of the 8 old bearings with SKF VPKG-3-03041 bearing units certified for Zone 21. The chain tensioning system was optimized and the ground conductivity of the installation was verified.

Measurable Results (KPIs):

• ATEX Safety: Full compliance with Directive 2014/34/EU and UNE-EN 60079. Risk of ignition due to bearings eliminated.
• MTBF: Increased from 18,000 hours to >40,000 hours. 80% reduction in major failures (from 2 to 0.4 failures/year).
• Downtime: Reduced from 24 hours/year to 4.8 hours/year (savings of 19.2 hours/year).
• Energy Savings: Reduction of consumption from 1.5 kW/bearing to 1.2 kW/bearing. Annual savings of 8 bearings * (1.5-1.2) kW * 8,000 hours/year * €0.15/kWh = €2,880.
• Maintenance Savings: 85% reduction in lubrication and labor costs.
• Payback Period: The investment of €6,400 in components was amortized in approximately 3 months, considering the savings in downtime, energy and maintenance.

This case underlines the technical and financial feasibility of ATEX modernization, even in environments with "still working" equipment.

8. Commissioning and Validation: Guaranteeing Conformity

Commissioning is the critical phase where it is verified that the modernized system operates according to specifications and complies with all ATEX regulations. Validation is not a one-time event, but rather an ongoing process.

• Operational Tests: Verification that all components, especially new and ATEX ones, operate within the design parameters (temperature, vibration, speed).
• Zone Classification Verification: Confirmation that the installed equipment is suitable for the specific ATEX zone classification.
• Visual and Documentary Inspection: Review of correct installation, ATEX labeling, certificates and Declarations of Conformity from manufacturers. Compliance with UNE 60079-17 Standard for inspection and maintenance of ATEX electrical installations.
• Intrinsic Safety Tests: If intrinsically safe circuits are used, verify safety barriers, grounding and energy calculations.
• Procedure Validation: Ensure that new operation and maintenance procedures comply with ATEX safety requirements.
• Final Commissioning Report: Detailed document that certifies the conformity of the modernized system with applicable regulations and design requirements.

9. Conclusion

Modernizing brownfield facilities with ATEX certified equipment is an essential strategy for the modern manufacturing industry. Beyond regulatory compliance, it represents an opportunity to significantly improve personnel and asset safety, optimize energy and operational efficiency, and ensure greater reliability and equipment life. Investing in advanced ATEX technology, such as SKF VPKG-3-03041 bearing units, offers a quick and tangible return on investment. UNITEC-D is your strategic partner for the acquisition of components both for the replacement of legacy elements and for the implementation of modern and certified solutions. Safety and efficiency are the pillars of industrial excellence.

Explore advanced solutions and certified components for your retrofit project. Visit the UNITEC-D E-Catalog.

10. References

• Directive 2014/34/EU of the European Parliament and of the Council, relating to the harmonization of the laws of the Member States on equipment and protection systems for use in potentially explosive atmospheres (ATEX).
• UNE-EN 60079-0: Explosive atmospheres. Part 0: Team. General requirements.
• UNE-EN 60079-10-1: Explosive atmospheres. Part 10-1: Classification of areas. Explosive gas atmospheres.
• UNE-EN 60079-10-2: Explosive atmospheres. Part 10-2: Classification of areas. Explosive dust atmospheres.
• UNE-EN 60079-14: Explosive atmospheres. Part 14: Design, selection and erection of electrical installations.
• UNE-EN 60079-17: Explosive atmospheres. Part 17: Inspection and maintenance of electrical installations.
• UNE-EN 1127-1: Explosive atmospheres. Explosion prevention and explosion protection. Part 1: Basic concepts and methodology.
• Directive 2009/125/EC of the European Parliament and of the Council, establishing a framework for the establishment of ecodesign requirements applicable to energy-related products.
• Directive 2012/27/EU of the European Parliament and of the Council, relating to energy efficiency.
• SKF migration guide for bearings in harsh environments (generic reference).