What is a non-sparking tool?
Non-sparking tool are tools made of special alloys that generate low energy sparks. The key principle to avoid an explosion is therefore to ensure that the energy of the spark a tool generates is lower than the ignition point of the gas in the atmosphere.
What non-sparking alloys exist?
The most common alloys are copper beryllium (also called beryllium copper or Cu-Be) and aluminum bronze (also called Al-Bron).
Although Cu-Be alloy is 20% – 40% more expensive than Al-Bron at the point of purchase, it has two important benefits:
- The energy of the spark it generates is lower than that of Al-Bron tools, and as a result, Cu-Be are considered safer since they can be used in the presence of all gas groups (including Group IIC).
- Cu-Be tools have superior mechanical properties, and therefore last longer. If used frequently, Cu-Be could generate considerable cost savings through lower tool replacements time.
In addition, Cu-Be non-sparking tools are non-magnetic, an important benefit if work is being carried out in the presence of a magnetic field.
How do I decide which alloy is the best option for me?
Cu-Be is the best choice in 90% of cases, as its best properties make it safer and more economical over time. In general terms, Al-Bron non-sparking tools are only competitive when four conditions are met simultaneously:
– The tool will be used very occasionally, not periodically.
– Great efforts will not be made.
– Complete non-magnetism is not required.
– Will not be used in IIC group atmospheres.
If all these conditions occur at once, the Al-Bron may be the best option. But if only one of these conditions is not met, then the Cu-Be is the right decision.
Are there other safe alloys apart from the Cu-Be and Al-Bron?
Other alloys available in the market include copper, tin bronze, brass or manganese bronze. However, these alloys are not a viable alternative to Cu-Be and Al-Bron tools due to their low hardness and resistance levels (between 4 to 6 times lower).
Copper, brass and tin bronze non-sparking tools are therefore mainly used in those special cases where a very low hardness level is required.
How about if there is Acetylene gas in the atmosphere?
Even if Cu-Be is the safest non-sparking tool alloy, there is one exception where they could represent an explosion hazard: the presence of Acetylene in the atmosphere.
Acetylene is a gas in the IIC group, and therefore Cu-Be alloys would not trigger its deflagration. However, acetylene is a substance that reacts with any alloy with a copper composition higher than 65%, creating a new, highly explosive compound, called copper Acetylide.
As both Cu-Be and Al-Bron non-sparking tools contain more than 80% of copper in their composition, they must never be used in acetylene environments. In such environments, steel tools would likely be safer than Cu-Be non-sparking tools.
