Flash Back Arresters

About Flash Back Arresters

Flash back arresters are essential safety devices that prevent dangerous reverse gas flow and flame propagation in oxy-fuel welding, cutting, and heating equipment. Fitted between gas cylinders and hoses, these protective devices act as one-way valves that stop flames from travelling back towards the cylinder during a flashback event. When activated, they quickly shut off gas flow and extinguish flames, preventing potentially catastrophic explosions or cylinder damage. MyToolShed.co.uk stocks flash back arresters from trusted brands including Draper and Sealey, with models specifically designed for oxygen and fuel gases such as acetylene, propane, and LPG.

All flash back arresters available at MyToolShed comply with BS EN ISO 5175 standards, ensuring reliable protection for professional tradespeople and DIY enthusiasts. These arresters typically feature robust brass construction with sintered flame arrestor elements that withstand extreme flashback conditions whilst maintaining normal gas flow during operation. Installing appropriate flash back arresters on both oxygen and fuel gas lines is not just good practice—it's an essential safety requirement mandated by HSE guidelines and workshop insurance policies throughout the UK.

Applications

• Welders and fabricators using oxy-acetylene equipment in workshops and construction sites
• Plumbers and heating engineers working with gas torches for pipe cutting, brazing, and soldering
• Metal workers and blacksmiths using oxy-fuel equipment for heating and forming metal
• Automotive workshops performing exhaust repairs, chassis work, and custom modifications
• Vehicle restoration specialists using gas welding and cutting equipment on classic cars
• Agricultural engineers maintaining farm machinery with oxy-fuel cutting and welding tools
• Demolition contractors using cutting torches for dismantling metal structures
• Maintenance departments in manufacturing, utilities, and facilities management
• Metal artists and sculptors using gas equipment for creative metalwork

Choosing The Right Flash Back Arresters

Gas type compatibility is critical—oxygen flash back arresters must only be used on oxygen lines, whilst fuel gas arresters for acetylene, propane, or LPG must match your specific fuel type. Never interchange these devices as they have different specifications and safety characteristics. For complete protection, you'll need arresters for both oxygen and fuel gas lines.

Standards compliance is non-negotiable. Only purchase flash back arresters that comply with BS EN ISO 5175 standards, ensuring the device has been properly tested and certified for UK use. MyToolShed.co.uk stocks arresters from reputable brands like Draper and Sealey that meet these stringent safety requirements.

Installation location affects protection levels. Flash back arresters can be fitted at the regulator outlet or inline within the hose system. Many professionals install arresters at both locations for maximum protection—regulator-mounted arrestors protect the cylinder, whilst inline arrestors provide additional protection closer to the torch.

Build quality matters for reliability. Look for robust brass construction with clear visual indicators (often a red flag or button) that pop up when activated, alerting you that a flashback has occurred and the device needs inspection or servicing.

Safety Information

Flash back arresters are mandatory safety equipment under HSE guidelines when using oxy-fuel gas welding and cutting equipment. Always install arresters on both oxygen and fuel gas lines according to manufacturer instructions, ensuring connections are gas-tight using appropriate spanners. After installation, conduct a leak test using approved leak detection fluid.

Inspect flash back arresters before each use for damage, corrosion, or previous activation. If an arrestor has been triggered during a flashback event, it must be inspected, serviced, or replaced according to manufacturer guidance—never simply reset and continue using without proper checks. If a flashback occurs, immediately close torch valves (fuel gas first, then oxygen), then close cylinder valves. Allow equipment to cool before investigation.

Frequently Asked Questions

Do I need flash back arresters on both gas lines?

Yes, absolutely. Both oxygen and fuel gas lines require their own specific flash back arresters. A flashback can occur on either line, and each gas type requires an arrestor designed for its particular properties. This dual protection is considered best practice by the HSE and is required by most workplace safety policies and insurance providers.

Can flash back arresters be reused after activation?

This depends on the specific model. Some flash back arresters are serviceable with replaceable components, whilst others are sealed units requiring complete replacement after activation. Quality brands like Draper and Sealey provide clear guidance in their documentation. Even serviceable models should be professionally inspected after a flashback event to ensure all components remain safe.

Are oxygen and fuel gas arresters interchangeable?

No, different gases absolutely require different flash back arresters. Oxygen arrestors are specifically designed for high-pressure oxygen environments, whilst fuel gas arrestors for acetylene, propane, or LPG have different internal components and pressure ratings. Never use an oxygen arrestor on a fuel line or vice versa—doing so compromises safety and invalidates certification.