Welding fume suction torch, how it works and why to use it

The suction torch is very common as a system of extraction of welding fumes in Northern European countries and generally in the “advanced” markets where there is a high sensitivity to the health protection of the welder and at the same time to energy savings. It is about a technical solution that has many advantages than the classic smoke suction systems, even if being technologically advanced requires a good technical culture and the willingness to change some process habits that the welder is not always willing to do.

Let’s see how it works

With regard to the decrees on occupational hygiene, the suction torch, like almost all the systems proposed by Secureair®, allows to stay below 70% of the maximum levels of pollution (TLV 5 mg/mc) established by law and therefore well below the limit of “area of action” within which preclinical signs of occupational disease cannot be detected. It should be noted that large companies require safety margins of 50% for air treatment equipment compared to the maximum limits allowed by law. For more information on TLVs see here.

Suction system: centralized or with single system?

The technical solutions are normally of two types, both require high pressure suction systems, different from each other only according to how many torches work in the department.

In case of a few locations (2-3 max) a single mobile or fixed aspirator for each is the best solution. They are equipped with high pressure turbine, integrated filters on board and better if there is also an automatic start control connected to the welding machine
In the case of many workstations it is necessary to create a centralized suction system with a network of pipes that connect the torches to a single turbine. The latest inverter technologies allow you to adjust the revolutions of the turbine according to how many workstations actually work with consequent energy savings.

The fundamental advantages of the welding fume extraction system with suction torches

1. Energy saving: The suction torch works efficiently with small air flows and large pressures, because the connecting pipes are all small in diameter. In this way you do not suck large quantities of air from the environment, for example avoiding the problem of heating in winter typical of the suction systems that suck air that we heated with great expenditure of economic resources,
2. No discretion of use: the operator cannot “choose” not to use the extractor or forget it as it happens with classic systems. Fume extraction is part of the process and is always used in this way and there is no loss of time to reposition the suction arm or other hoses (proven savings of up to 50 minutes per turn),
3. Indispensable in the case of large pieces to be welded: thanks to the torch with integrated extraction, the operator can also reach difficult working points with guaranteed smoke extraction. This would not be possible with classic arms or other hoods.

Some advice from our experienced technicians

In order to obtain the best result, both for the fume extraction and for the technical features of the welds, it is advisable to use the following precautions:

Keep the mouth of the torch as vertical as possible in order to capture the fumes more effectively (compatible with the welding characteristics), Keep the torch as close as possible to the welding point to achieve better capture and protection of the weld bath.
The torch should always be held at an inclination of approximately >15° <45° (EN 60974-7 standard) compared to the melting bath to get the best suction together with better welding quality.
The maximum distance between the gas nozzle and the melting bath must always be kept below 1 cm (EN 60974-7 standard), especially for corner welding, this to avoid the risk of porosity or oxidation in welding.