Can Stainless Steel Be Used for Piping?

Piping is used in almost every industry from power generation to food production, it is the backbone of many processes, carrying fluid and gases anywhere from a few feet to hundreds of miles.

Stainless steel pipes are often used for corrosion resistance and versatility. In this article we’ll discuss the most common implementations and benefits of stainless steel piping.

Common Uses for Stainless Steel Pipe

Stainless steel pipes find applications in a wide range of industries:

Oil and Gas processing

From pipelines for raw or refined products to ancillary processing, the oil and gas industry uses stainless steel pipe extensively. Its high strength and corrosion resistance mean it is long lasting and maintenance free.

Water Processing

Both clean and wastewater processing need methods of transportation that can be long-lasting and easily cleaned. Stainless steel is easier to join and fabricate than plastic piping and can hold significantly higher pressures.

Furthermore, its corrosion resistance means the infrastructure can last a long time without needing replacement, coating, or refurbishment.

Pharmaceutical and Food Production

Where the end products being processed are to be consumed, high levels of cleanliness are required. This not only means that fabricated components need to be hygienic when manufactured, they also need to be able to be cleaned in the future, and not susceptible to corrosion.

Stainless steel pipe is heavily used in food manufacturing, for carrying everything from milk to concentrated syrup. It is also very resistant to acidic substances, which is vital in many food and drink manufacturing processes.

Grades of Stainless Steel

There are numerous grades of stainless steel, each one well suited to different environments, these range from high-iron content ones used in low-cost parts to high-strength high-nickel alloys used in the aerospace sector.

The most commonly used grades however are in the 300 series, including 321, 304, and 316. Stainless steel pipes are primarily used in 304 and 316 grades.

304 Grade Stainless Steel

Usually, the cheaper of the two we stock, 304 grade is still widely used in typical pipe applications, such as within the food manufacturing industry, hospital equipment and oil and gas.

It is resistant to various acidic environments such as Acetic, Nitric and Citric acids, it is easily welded, machined and formed.

316 Grade Stainless Steel

With slightly higher tensile strength and hardness, 316 stainless steel is often used in mechanical applications in industries requiring corrosion resistance, such as pump shafts, machined valve bodies and more. It is also easily found in pipe, plate and sheet form.

316 contains 2% more nickel than 304, but slightly less chromium. It is also easily welded, machined and formed.

Is Stainless Steel a Good Option for Pipe?

Stainless steel is an ideal choice for pipe, as it has high strength, easy workability and excellent corrosion resistance, the latter being especially important for liquid and gas carrying applications, where cleanliness is important.

The ease of fabrication is another reason why stainless steel is widely used in industry, as it is easily welded, machined and formed. This enables the cost-effective manufacture of all manner of parts from ductwork to high pressure piping.

Alternatives to Stainless Steel Pipe

Galvanized or Painted Steel

If corrosion resistance and cost effectiveness are key, starting with mild steel material and using a coating process such as galvanizing, plating or painting might be an option. This can achieve a lower upfront cost.

The downside is that these coatings are not typically resistant to wear, meaning liquids containing particulates can end up wearing through the coating, enabling the material to corrode.

Aluminum

If weight is a primary consideration, aluminum can be a good alternative, however, it does have a lower tensile strength and therefore typically cannot hold as much pressure as stainless steel or carbon steel pipes.

Conversely, aluminum does not corrode, meaning no coating is needed to prevent rust, and it is also easily workable.

Advantages of Stainless Steel Pipe

Corrosion Resistance

Not having to protect the surface of the metal from corrosion makes stainless steel one of the most invaluable pipe materials there is, from both a longevity and maintenance standpoint.

Prolonging the lifespan of the part as well as removing the need to re-painting in the future cuts down overall costs.

Strength

Whilst the strength of stainless steel is generally comparable to that of steel, with some alloys of both bettering the other, its strength over its corrosion free alternatives is where it shines. Stainless steel is stronger than aluminum, copper and plastic.

Workability

Unlike some high-strength nickel and aluminum-based alloys, stainless steel is very easy to machine, weld and form. This makes manufacturing components from it reasonably convenient and cost effective.

This also enables the cost effective manufacturing of other components used in conjunction with stainless pipes such as valves, threaded components and formed components such as tees or elbows.

Wide Range of Grades and Section

Due to both the worldwide and long-term use of stainless steel, there are many grades available, allowing almost all specific applications to be catered for. From highly acidic environments to offshore uses.

This has also facilitated the secure supply of a wide range of sizes, finishes and wall thicknesses, allowing engineered solutions to be catered for, from ¼ inch diameter up to 30” or more.

Disadvantages of using Stainless Steel for Pipe

Cost

Stainless steel is considerably more expensive than mild steel, even in pipes and tubes. Items such as welding wire, valves and fittings made in stainless steel are also more expensive than their steel or brass counterparts.

Weight

At around 10% heavier than mild steel, stainless is not a lightweight material. Especially when compared to aluminum, although stainless is much stronger. If your pipe is not due to handle high pressures, it might be worth considering a lighter material.

Galling

In instances where two stainless steel components interface using a thread, such as a fitting screwing into a valve, galling can occur. This makes the two parts hard to separate and, in some circumstances, can damage the thread. This means an anti-seize compound is often used on stainless steel pipe fittings.

Buy Your Stainless Steel Pipe from Metals Supermarkets

Regardless of the complexity or size of your project, if you need stainless steel pipe, we can help. Metals Supermarkets keeps a wide range of sizes and the most common grades in stock, with cut-to-length services available nationwide.