A term very commonly used in the steel industry, galvanisation is a manufacturing process through which a thin layer of zinc is applied to steel to offer greater rust and corrosion protection. As compared to non-galvanised steel, galvanised steel has a longer life and durability, which is why it is often used in industrial applications where strength, durability and corrosion-resistance in steel are paramount. If you’re wondering whether to choose galvanised steel pipes over stainless steel pipes for your industrial facility, here are some things you should know about the material:
What is galvanisation?
Although there are many different ways to galvanise steel, the most common is hot-dip galvanisation. In hot-dip galvanisation, treated steel is dipped into a vat of hot, molten zinc at a temperature of about 460°C, which creates a protective layer of zinc over the metal. By dipping the metal into hot zinc, a metallurgical bond is created between the two materials. After it is removed from the vat, the zinc-coated metal reacts with the oxygen in the environment to create zinc oxide, which then reacts with carbon dioxide in the air to form zinc carbonate. This zinc carbonate is the substance that forms the protective layer on top of the metal to protect it from rust and increase its longevity.
Other methods of galvanisation include continuous galvanisation, thermal spray, electroplating, sherardizing and thermal diffusion and mechanical plating. To prevent damage due to corrosion in mild steel, Jacob UK’s pipes and pipe components are protected to enable them to withstand various conditions. We offer different product groups for the stainless steel modular pipework system, including powder coating, spray priming and galvanising. All components described as “galvanised” on our catalogues and website are hot-dip galvanised, and other accessories like pull-rings, ball joints and air regulators are electro-galvanised.
How strong are galvanised steel pipes?
The strength of galvanised steel pipes comes from the strength of the steel being galvanised, not the actual galvanisation process itself. All galvanisation does is coat the surface of the steel with a protective covering that prevents it from rusting, but the actual strength of the pipe depends upon what is added to the metal when it is being manufactured. However, galvanising steel may make it more ductile and easier to work with.
What are galvanised steel pipes used for?
Our galvanised steel pipes and pipe components are used in all kinds of industries but are primarily used in agricultural applications where food safety isn’t applicable and applications where stainless steel isn’t a requirement but longevity is necessary. Some examples include animal feed transfer, wood chip transfer, wood pellet fill for biomass and extraction in the woodworking industries.
Is galvanised steel dangerous?
Galvanised steel is not meant to be used in high-temperature applications as zinc fumes are released from the surface of the metal when it is heated. In accordance with the US Department of Health and Human Services’1997 Food Code, Section 4-101.15 Galvanised Metal, Use Limitation, “Galvanised metal may not be used for utensils or food contact surfaces of equipment that are used in contact with acidic food”. This is because acidic foods are particularly aggressive to the corrosion of the zinc coating, which is converted to zinc salt when it comes in contact with acidic foods and beverages.
While galvanised steel may not be dangerous in most other applications, it is always a better idea to choose stainless steel for applications that require food safety or high temperatures. See some common applications in the section above.
How long do galvanised steel pipes last?
As with all applications, the average lifespan of galvanised steel pipes depends on their use. The key feature of all of Jacob UK’s modular range, including galvanised steel pipes, is that if wear occurs, the lipped end and clamp system means that the entire system will not need to be changed but just the singular point of wear. This helps industries keep costs down by minimising downtime in the case of a breakdown and requires minimal manpower to fix the problem.
Does galvanised steel rust?
If not maintained properly and exposed to the wrong conditions, galvanised steel can rust. Although galvanised steel takes a very long time to rust, this duration depends largely upon the type and thickness of the protective galvanised zinc coating. Even if the zinc coating is scratched off from certain places, it will continue to protect the nearby steel through cathodic protection until largescale damage occurs.
No material can last forever. Regardless of how high the quality of your galvanised steel pipes is, inevitably they will undergo wear and tear. The benefit of Jacob’s modular range of stainless steel and galvanised steel pipes and pipe components is that the part that has gotten damaged can easily be removed and replaced without having to take the entire system apart. This saves time and manpower and helps keep costs down.