Galvanized Steel Pipe

Galvanized Steel

Metals like aluminum and stainless steel may not rust like steel. However, the cost of using these materials are significantly higher. To save money, many choose to prolong corrosion by using galvanized steel. Galvanization is a post-manufacturing or finishing, the process used to delay steel corrosion, particularly from rusting and accidental damage. The galvanizing process results in a thick, durable outer layer of zinc on the substrate or steel. This outer layer can protect the underlying steel from a variety of damages.

Hot Dip Galvanizing

There are a few methods used to galvanize steel, but in the steel pipe industry, the most relevant method is continuous “hot dip” galvanizing. Typically in this scenario, a customer will order some steel products to be hot dip galvanized. The supplier will then send the order to a third-party for galvanizing. The third party will hot dip the order.

Hot dip galvanizing is a straightforward process. The steel is first chemically cleaned or cleaned via sandblasting. Then, the steel is pickled to remove mill scale. A flux, often zinc ammonium chloride, is applied to the steel to prevent flash rusting. Following this step, the steel is dipped into a molten zinc bath. The molten zinc bonds to the iron in the steel, thus creating a protective coat on each surface of the steel. The zinc-coated steel is cooled (quenched) in a cooling tank and re-stenciled once cooled. The outer layer will not crack, flake or peel when a steel sheet is spun into a finished part.

Stainless steel prevents corrosion similar to galvanization, however, galvanization of steel is far more economical. If you are working with a budget, you will want to look into galvanizing existing stock versus using more exotic materials.

Benefits of Galvanized Steel

Galvanized steel is most commonly used for construction. Galvanizing achieves the following two lines of defense:

  1. Sacrificial Layer

The zinc coating provides a physical barrier that serves as a sacrificial seal. As a result, any damage from potential impact, scratching, drilling and cutting will affect the outer zinc barrier first, leaving the underlying steel protected.

  1. Protection from Oxidation

Galvanizing provides additional protection from corrosive substances in the atmosphere. The zinc is more reactive than the iron in steel, so atmospheric oxygen will first react with the zinc rather than the iron, thereby oxidizing the zinc coating and delaying corrosion to the underlying steel.

Galvanized Pipe

When Not to Use

Galvanizing is an inexpensive way to extend the lifespan of steel products. It is more economical to consider galvanizing existing stock, versus purchasing more exotic metals. However, hot-dip galvanizing is not ideal for every project.

Galvanizing cannot protect steel components and steel parts that are constantly exposed to corrosive substances, such as acid and acid rain. Acid can chemically react with the zinc coating. Such reaction is particularly harmful in the food industry. Likewise, galvanizing is not suitable for nuts and bolts sizes US ⅜” or smaller because the zinc coating can overfill the threads and consequently reduce the product strength. In both of these situations, stainless steel is a better option.

Galvanizing has other limits. Salty environments, salt water and prolonged exposure to weather can shorten the lifetime of galvanized barriers. The lifespan of galvanized steel in these circumstances is much shorter than that of galvanized steel applied in more benign environments.

Overall, galvanized steel is a smart alternative to pricier metals like stainless steel and aluminum, when appropriately applied. They are well-protected from corrosion and provide the strength necessary for a variety of heavy-duty projects.

Galvanized steel pipe is the carbon steel pipe that is coated with a protective layer of zinc. The zinc layer works as a sacrificial layer which basically means that this zinc layer will get the rust before the carbon steel beneath it does. The galvanized layer strengthens the anti-corrosion performances of steel pipe. Zinc is used because the first kind of material that ends up being corrupted is the zinc and not the steel. The zinc layer stops corrosion speed and prolongs the life of the steel pipe.

Galvanized steel pipe has many different users in everyday projects. The most common use for galvanized steel pipe is in construction when creating awnings, balconies, and fences. It is used in electronics, in computer casings and many precision instruments. Cars and aircraft are large consumers of galvanized steel through the hood, oil pans, parking brakes, and roofing.

ADDITION TO BENEFIT SECTION

  • Low initial cost- The galvanization process usually costs less than other popular methods of steel.This is because the other steel methods are often labor intensive. Galvanization requires less labor which makes it not affected by the cost increase
  • Long life- Galvanized steel pipe can last more than 50 years in many rural areas and more than 25 years in exposed areas.
  • Toughness- The initial coating makes the steel very rugged which makes the products resist damage in transport to service
  • Fast assembly- once the steel product is manufactured, there is no need to prepare or paint the coating.