Seamless Pipe and Welded Pipe Price Comparison

Seamless Pipe vs. Welded Pipe: Which One is More Expensive?

In most cases, seamless pipe is more expensive than welded pipe. Typically, seamless pipe of the same specification costs 20% to 50% more than welded pipe. The price difference can be even greater for certain specifications and materials.

Analysis of Factors Influencing the Prices of Seamless and Welded Pipes:

1. Production process

Seamless pipes are made by directly heating steel billets to a certain temperature and processing them through processes such as perforation, heating, and hot rolling. They have no welds and are a homogeneous steel pipe. Because the material has no seams or welds, it has high strength and corrosion resistance, and has a wider range of applications, such as petroleum, chemicals, natural gas, ships, construction and other fields.

Welded pipe is a steel pipe made from a pipe blank pressed from a steel plate or steel strip, which is made through multiple processes of bending, welding and cutting. The production process of welded pipes is simple, the production efficiency is high, there are many varieties and specifications, the equipment investment is small, and the price is cheap. Because of its relatively low cost, it is widely used in construction, machinery, aviation and other fields. However, welding will change the grain structure and mechanical properties of the steel, making the strength and corrosion resistance of the welded pipe lower.

Seamless steel pipes are manufactured through a special process, and the raw material of seamless pipes is round steel. Good round steel, especially tube blank steel, has less impurities and good forging effect, so the yield will naturally be higher. Seamless steel pipes are formed in one step during the rolling process. The processing of seamless steel pipes has been changed from solid round steel to hollow round steel. During the piercing process, cutting and high temperatures are required. Wastewater and slag need to be treated during the pickling process. Natural gas, etc. are used in the annealing process, and each process requires post-processing, which also consumes a lot of money. In addition, seamless tubes have a greater eccentricity due to process reasons, which, depending on the application of the tube, must be reworked by expensive grinding.

2. Quality requirements
The quality requirements of seamless steel pipes are relatively high, and it is necessary to ensure that there are no internal defects, a smooth appearance, and no burrs. However, due to the limitations of the production method, it is difficult to avoid defects such as cracks and pores in the welded parts of welded steel pipes. High-quality seamless steel pipes require higher raw material and precision processing costs, and the price is correspondingly higher.

3. Service life
Seamless steel pipes have higher strength indicators such as compression resistance and tensile strength than welded steel pipes, and have a longer service life.

4. Market demand

Seamless steel pipes are widely used in petroleum, chemical industry, machinery, rail transit and other fields. Due to the particularity of applications and quantity requirements, the price of seamless steel pipes is relatively high. Affected by market competition and market demand, the price of welded steel pipes is relatively low.

Technological development:
Modern inspection technology has found that there are edge deviations, pores and scratches on the surface and welds of welded pipes. Therefore, the quality of welded pipes is not inferior to seamless pipes. Therefore, the most advanced methods are used to weld steel pipes, and the quality is the same as seamless pipes. For the sake of completeness, final heat treatment should usually be factored into the price. Nonetheless, welded pipes will maintain their price advantage.

Seamless and Welded Pipes: How to Choose?

The key isn't "price" but "value." Simply comparing prices is meaningless; the key lies in your application. Do you pay for performance or cost?

When Should You Choose Welded Pipe? - Pursuing Economy

Welded pipe is the wisest and most economical choice when your application meets the following conditions:
1. Low pressure or non-pressurized applications, such as furniture, guardrails, stairs, and conduit.
2. The media is not highly corrosive, such as ordinary tap water or air.
3. Safety requirements are low, and even if a leak occurs, the consequences are minimal.
In these cases, choosing seamless pipe would be "overperforming" and a waste of money.

When is it essential to choose seamless pipe? - Pursuing Reliability and Safety

When your application encounters any of the following conditions, you must choose seamless pipe. The premium is a necessary safety cost:
1. High-pressure, high-temperature environments, such as boiler pipes, high-pressure steam pipes, and hydraulic systems.
2. Highly corrosive or hazardous media, such as chemical pipelines and oil and gas transportation.
3. Applications requiring extremely high safety and reliability, such as oil drilling pipes and aircraft parts.
4. Applications subject to alternating or fatigue loads, such as vibrating pipes, where welds can become a source of fatigue.
In these situations, choosing welded pipe to save money is a significant safety risk, potentially leading to catastrophic accidents and significant economic losses.

Conclusion:

This article analyzes the price difference between seamless steel pipes and welded steel pipes from four aspects: production process, quality requirements, service life and market demand. Overall, the price of seamless steel pipes is more expensive than welded steel pipes. Because the production process and quality requirements of seamless steel pipes are higher, and the market demand is also more specialized. But this does not mean that welded steel pipes are cheaper in all cases, and they need to be considered comprehensively based on specific circumstances. When purchasing steel pipes, you need to choose based on specific circumstances. Not only should you consider price factors, but also many aspects such as applicability, quality, and usage.

Read more: Schedule 40 Steel Pipe or ERW pipe vs Seamless Pipe Cost