Due to the changes in HSE enforcement expectations in relation to the control of exposure of welding fume, including that from mild steel welding, safe removal of welding fumes at source has become a mandatory requirement.
This all-new range of MIG welding torches with on-torch welding fume extraction/on-tool extraction/welding torch extraction offer a solution to the current HSE requirements, extracting the weld fumes from the weld point.
According to the most recent HSE welding fume facts, this is where the concentration of harmful substances will be highest, in what is called the 'plume of fume' that rises immediately from the welding arc.
That said, a very important consideration when extracting welding fumes directly from the MIG welding torch, is that the shielding gas is not affected. Removal of shielding gas as we know causes porosity in the weld.
This range of MIG torches are fitted with a suction control valve on the handle to adjust the extraction flow rate while welding. This is very important, for example when welding into a corner, and the area around the weld becomes much more limited.
It is critical that the right balance is found between removing all the fumes yet not causing porosity, and this unique feature is the solution to this potential problem.
Why use on-torch welding fume extraction?
If used correctly without compromising weld integrity, on-torch fume extraction is the most effective fume control for MIG welding as it removes the majority of harmful fumes. On-torch can reach welds where conventional fume extraction arms cannot.
How does on-torch welding fume extraction work?
A welding torch with fume extraction attached at the tip of the torch extracts fumes directly above the welding pool. The nozzle at the end of the torch has an opening which is where the harmful fumes are extracted when welding. The fumes are suctioned through the torch, treated and filtered in the collector before being safely released.
On-torch fume extraction is effective because
- It is integrated with the welding gun
- It moves with the weld
- It is very close to the source at all times
- It does not rely on the welder to reposition the extraction to maintain good fume capture.
- It can reach welds where a conventional arm cannot
Types of on-torch fume extraction?
Like standard MIG torches, on-torch extraction is available in various lengths, amperages and they can be air cooled or water cooled.
When is on-torch fume extraction most effective?
Research suggests that, on-torch is most effective when welding on a flat surface, either parallel or vertically.
How small or large should the workpiece be when using on-torch extraction?
It can be used on small, medium, large and extra large workpieces. For example, 1m x 0.5m up to 2m x 4m.
Are there any limitations to on-torch fume extraction?
- It is recommended that on-torch fume extraction is used in conjunction with other control methods as not all of the fumes are captured e.g. wearing air fed welding masks or ensuring the room is well ventilated.
- The extraction unit needs to be located close to the welding area. Therefore, it is not always practical to use when welding is carried out while working at height.
- Research has shown that on-torch is more effective when groove welding on a flat surface (eg. downhand, horizontal or vertical) than when fillet welding or groove welding in the overhead position.
- The diagram below shows on-torch fume extraction for MIG welding.
Disadvantages of on-torch welding fume extraction
- The MIG gun is heavy, welding tiring long term will be tiring
- The welding gun is too bulky, making it awkward and difficult to effectively reach the weld point
- Some MIG guns may not extract enough fumes. However, HSE recommend combining fume extraction methods
- Shrouds that are too close to the welding joint can lead to porosity in the weld as the gun extracts the shielding gas
These potential issues should be taken into consideration during purchasing decisions to ensure you are using a fume extraction gun that is right for you.
MasterWeld fan-type extraction nozzle
The MasterWeld fan-type extraction nozzle fitted to the torch ensures 100% removal of the welding fume without affecting the shielding gas. It does this by pulling the fumes from around the immediate area of the weld point, rather than from the end of the gas nozzle.
Need further technical support? Ensure you are HSE compliant. Call us free to discuss your requirements on 0800 975 9710
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