A prevailing misconception asserts that oxygen is flammable. However, while being essential for combustion, oxygen is by no means an element that can erupt in flames. It is, in fact, an accelerator, meaning that when it, or any other oxidizing agent, combines with fuel at the right temperature, it initiates the chain reaction that we know as fire. This process holds true with oxy-fuel torches.
Oxy-fuel torches, the materials, construction, safety, performance, test procedures, and marking of which are addressed in CGA E-5-2017 – Oxy-Fuel Torch Standard – Sixth Edition, function to convey and control fuel and oxygen in a safe manner. The torch delivers these two main components to the tip, where the mixed gases can be continuously burned. Pure oxygen must be delivered to the tip for the cutting function. Oxy-fuel cutting, due to its availability and low-cost, is suitable for a plethora of heating, welding, and cutting applications, ranging from scrap cutting to precision cutting in fully automated systems.
Regardless of its application, any oxy-fuel torch is expected to perform in a manner that is both safe for the user and non-detrimental to the performance and reliability of the tool. When it comes to safety, the most common mishap while using torches is, unsurprisingly, the user sustaining a burn. Major issues with combustion stability in oxy-fuel torches include backfire, sustained backfire, flashback, and backflow. CGA E-5-2017 addresses tests for assuring the stability of a torch in relation to these concerns.
However, while tests do secure the integrity of a torch’s performance, it is important to note that these issues are often caused by improper torch use and maintenance. As stated in CGA E-5-2017, “Initial and recurring training on the proper use of torches is important for the safety of the workforce.”
Dependable performance of oxy-fuel torches can be instilled into the tools during their construction. For example, this involves using materials for the torches and cutting attachments that minimize the effects of gases and following specific practices for gas tightness and venting. Specifications for these actions, as well as testing procedures associated with related concerns like durability, are addressed in CGA E-5-2017.
The oxy-fuel torch standard details much regarding the torch’s performance, but it does not specify specific gas flow rates, which are left up to the manufacturer’s discretion. However, most welding and cutting applications have industry recommended flow rates that should be used as a general guideline. The minimum recommended flow rates are included in informative Appendix A.
The CGA E-5-2017 standard, which was written and developed by the Compressed Gas Association, an ANSI-accredited standards developing organization, is the sixth edition of the standard for oxy-fuel torches. Any changes made to this revision are visible throughout the document, as the altered text is underlined.
CGA E-5-2017 – Oxy-Fuel Torch Standard – Sixth Edition is available on the ANSI Webstore.