Root Protection in Special Welding
Process

Gas blend for all root protection process.

The demand of modern industry always requiresgreater competence and production quality

The requirements for material and quality of vessels and pipes have increased exponentially in recent years, especially in the chemical-pharmaceutical, scientific and food sectors.

Ar
Argon
N2/H2
Formingas 5 - 10
Ar/H2
Sanarc H5
Prevent Oxidation

One of the fundamental requirements imposed regarding welding pipes is to prevent oxidation of the weld during the first step.



The shielding gas flowing from the welding torch only provides oxidation protection on the upper side of the weld. Forming the underside of the weld by inert or reducing shielding gases prevents or reduces oxidation of the weld root and reduces or prevents tarnish (scale layers), which are the starting point of corrosion even in high-alloy steels. The forming gas additionally supports the forming of the root.

Metal reactivity

Every single material requires a

specific root protection gas.


Carbon steel, stainless steel, Duplex and Superduplex,

aluminium, and many other gases have different

metallurgical characteristics and reactivity to air.

The choice of the inert gas or reducing mixture, must be

made by following the compatibility criterion of the

material to weld and critical aspects of the atmosphere

generated inside the tank - tube to weld.


There are on the market, devices and analysers allowing

a correct and safe use of the reducing gas, thus avoiding

waste of gas or incorrect use, which voids the operating

result.

Root protection
This practice has becomeincreasingly important in weldingprocesses, especially in thechemical, pharmaceutical andfood fields, with the aim ofobtaining a welded joint free ofsurface oxidisation, also on theopposite part where it is welded.
Nippon Gases recommends the use of nitrogen or argon gas mixtures with small amounts of hydrogen. It must be ensured that the ambient air has been sufficiently evacuated from the seam area and that sufficient forming gas is supplied during the entire welding process without causing turbulent flow. When using hydrogen mixtures (reducing effect), even greater attention must be paid to the relevant safety rules during forming.
Mixture on site

Potential production of the right onsite gas mixture.

Gas Mixer

Nippon Gases is able to meet the specific requests to generate onsite mixtures through the design and construction of specific gas mixers also, including remote control.

Form of supply
Cylinder
Packaged
Bundle
Package
MicroBulk®
Liquid
Tank
Liquid

Testing

Any questions?
Contact us
Do you still have questions?
In Nippon Gases we have developed various qualities of gases to adapt to your applications. Call us or write to us and we will help you get the most out of it.