Span gas cylinder online shopping UK: Helium / argon mixtures are sometimes used for their higher heat characteristics. Gas mixtures, usually 25% helium and 75% argon are sometimes used and can help to increase travel speeds when AC – gas tungsten arc welding. Mixtures of more than 25% helium for AC – gas tungsten arc welding are used, but not often, as they can tend to produce instability, under certain circumstances, in the AC arc. Pure helium or high percentages of helium (He-90%, Ar-10%) shielding gas are used primarily for gas tungsten arc machine welding with direct current electrode negative (DCEN). Often designed as seam welders, the combination of GTAW – DCEN and the high heat input from the gas used can provide fast welding speeds and outstanding penetration. This configuration is sometimes used to produce full penetration butt welds, welded from one side only, onto temporary baking with no vee-groove preparation, just a square edged plate.
If you have been in the industry for any length of time, you will know the most common examples. This includes the likes of argon, helium, or carbon dioxide. Each gas offers its own unique properties when welding, and a case could be made for any of them. Carbon dioxide, for example, is low cost. It also makes for inferior welds, letting too much oxygen in. Argon, on the other hand, might be the perfect replacement.
WSD (weldingsuppliesdirect.co.uk) supplies a wide range of shielding gases specifically designed to optimise performance in particular conditions. In vehicle repair and manufacturing, argon-based gas mixtures are commonly used to MIG weld carbon and low alloy steels. Argoshield Light is one of those choices. It’s ideal if you are welding thinner carbon steel ranging from 0.6 to 5mm in thickness. The addition of oxygen to Argoshield increases arc stability to minimise spatter and fast weld speeds with its low heat input reduce distortion. So it’s perfect for our earlier example where the components of a car are being painted or powder coated after welding. Read extra details on Calibration Gas Regulator.
A perfect welding result, without impairment of corrosion resistance and mechanical properties, can only be obtained when using a backing gas with very low oxygen content. For best results, a maximum of 20 ppm O2 at the root side can be tolerated. This can be achieved with a purging setup and can be controlled with a modern oxygen meter. Pure argon is by far the most common gas for root protection of stainless steels. Formier gas (N2 + 5 – 12% H2) is an excellent alternative for conventional austenitic steels. The gas contains an active component, H2, which brings down the oxygen level in the weld area. Quad gases are mainly used within Marine environments. Quad gases are a four gas mix. Supplied in a range of lightweight cylinders and made from aluminum. Both reactive and non-reactive mixtures are available.
Many of the gases fall within the scope of the Control of Substances Hazardous to Health Regulations (COSHH) 2002 (Amendment) 2004, which require that exposure to them is maintained below concentrations known as Workplace Exposure Limits (WELs). WEL values are given in Guidance Note EH40 from the Health and Safety Executive (HSE), which is usually updated annually. Source: www.weldingsuppliesdirect.co.uk.
