PD CEN TR 15339 — Thermal Spraying Equipment Safety Requirements Series

🔥 PD CEN/TR 15339 is a Published Document series issued by BSI adopting the European Committee for Standardization technical report CEN/TR 15339, providing systematic requirements for machinery safety and occupational safety of thermal spraying equipment. Thermal spraying processes (flame spraying, arc spraying, plasma spraying, HVOF hyper-velocity oxy-fuel spraying, cold spraying, etc.) rely on high temperature, high velocity, combustible gases and powder feedstocks, so the equipment itself carries multiple risks of explosion, fire, burns, noise, dust and electricity. Developed by CEN/TC 240 (Thermal spraying), the series gives manufacturers a unified framework for designing safe equipment and users a framework for safe operation.

1. Series Structure and Document Scope 📌

2. General Requirements (Part 1) 🧭

Part 1 establishes the overall framework for thermal spraying equipment safety, centred on “safe machinery design + market placement compliance”. Its main content:

• Design and construction of safe machinery: follow a safe design procedure, complying with the essential health and safety requirements (EHSR) of machinery legislation (e.g., the Machinery Directive).
• Technical documentation and construction file: establish a technical file and construction file recording risk assessment and safety measures.
• Placement on the market and putting into service: covers instructions, marking and declaration of conformity, ensuring equipment meets regulatory requirements when placed on the market.

This part stresses that risk assessment is the foundation of whole-life safety: identify hazards and take protective measures at each stage from design, manufacture, transport, installation, commissioning, use to maintenance.

3. Torches and Their Connection and Supply Units (Part 3) 🔫

The torch is the core actuating component of a thermal spraying system and the danger point closest to high-temperature, high-pressure gas flow. Part 3 gives safety characteristics of torches and their connection and supply units by spraying process type:

• Flame and HVOF spray torches: emphasise flashback prevention, fuel/oxygen ratio control, cooling requirements and ignition procedures.
• Cold spray torches: strength, pressure reduction and relief of high-pressure gas lines (up to several MPa).
• Arc spray torches: wire feeding, electrical insulation and arc shielding.

The standard also specifies requirements for connectors between torch and supply units (mistake-proofing, anti-loosening, sealing), and safe design of spray nozzles and powder conveying lines.

4. Gas and Liquid Fuel Supply (Part 4) ⛽

Part 4 focuses on the fuel and gas systems supporting thermal spraying. Its content covers:

• Gases for thermal spraying: classification, purity and storage of fuel gases (acetylene, propane, hydrogen, natural gas), oxidants (oxygen, compressed air) and inert gases.
• Safety-related features of gas, liquid fuel and cooling-water supply: line materials, connectors, pressure reducers, flow control, check valves and relief devices.
• Potential hazards: leakage, flashback, overpressure, explosive mixtures and toxicity of combustion products.
• Safety requirements and protective measures: ventilation, gas monitoring, emergency shut-off, marking and procedures.

The standard stresses that fuel-gas lines must be strictly separated from oxygen/air lines and protected against wrong connection; pressure reduction and flashback prevention are key safety barriers; and workshops should have adequate ventilation and gas detection.

5. Powder Feeding and Ancillary Systems (Parts 5/6) 📦

Part 5 covers powder and feeding systems, involving powder conveying, hoppers, metering devices and dust control; combustible metal powders (especially aluminium, magnesium) present dust-explosion hazards requiring explosion protection and dust extraction. Part 6 covers ancillaries (e.g., grit-blasting equipment, turntables, manipulators) and workshop layout, involving ventilation, noise insulation, fire compartments and ergonomics. Together they form the overall safe environment of thermal spraying workplaces.

6. Engineering Practice Application 🛠️

• 🔍 Equipment selection: when purchasing thermal spraying equipment, check its CE/UKCA marking, compliance documents and construction file to confirm compliance with the series safety requirements.
• 🔧 Installation and commissioning: per Part 4, standardise gas-line connections, implement leak testing, verify regulators and check valves, and establish ignition/shut-off procedures.
• 📊 Operation management: establish work-permit systems, require certified operators, and periodically inspect hoses, connectors, sensors and alarm devices.
• 📋 Dust and ventilation: implement dust extraction and explosion protection for combustible metal powders, maintain workshop ventilation and gas monitoring to prevent explosive atmospheres.

7. Frequently Asked Questions ❓