Carbon cold-drawn seamless steel tube is the most common component in process piping. It has the unique advantage of high strength, wide availability, and many connection possibilities (for example: screwed, butt-welded, and socket-welded).
Cold-drawn carbon steel seamless tubes are more efficient in tolerating pressure and heat and have an excellent surface finish. You should select steel pipe per the required strength and durability for the specific application. You should also look for the required ductility and machinability to form them accordingly into piping spools.
The pipe must tolerate handling the application’s high pressures, temperatures, and corrosion conditions. You can only meet these requirements if you choose pipes that seamless pipe manufacturers produce using the appropriate ASTM or API standards. Whether you choose stainless steel, carbon alloy, or any other metal pipes, manufacturers must follow the standards to produce high-quality pipes.
Application areas:
Carbon steel pipe is meant for gas, liquid, steam, and belowground services.
Though manufacturers ideally do not recommend carbon pipes for corrosive services, you can use them in acidic services. However, you should be careful about how much you expose the pipes to the acidic environment.
Steel-grade used:
There are different grades or strengths of carbon steel pipe, and they are available in various wall thicknesses. Therefore, line pipe suppliers use different allowable stress levels to determine what wall thickness they require. The allowable stress is a concern of both the manufacturer’s method and the material’s metallurgy.
For hot-rolled or cold-drawn steel seamless tubes, there are various piping specifications provided by ASTM and API guidelines:
- The most widely used piping specifications are ASTM Specifications A-53 and A-106 and API Standard 5L (for process lines).
- The principal wall thicknesses are scheduled (Schedule 40, Schedule 80).
- Wall thickness weights are defined as STD, XS, and XXS.
- Both ASTM A53 and ASTM A106 pipes are fabricated seamlessly or seamed, by ERW, in Grades A and B. Grades B have higher tensile strength.
- There are three grades of ASTM A106 —Grades A, B, and C, increasing tensile strength.
Strength:
In past years, most manufacturers produced cold-drawn seamless steel tubes from Grade B steel that has a minimum yield strength of 35,000 psi. However, the construction of high-pressure, large-diameter, cross-country transmission lines created a need for high-strength field-weldable steel that would substantially save steel tonnage. As a result, suppliers developed API Grades X-42 through X-70 with 42,000-70,000 psi strengths.
Pitting corrosion resistance in carbon steel pipes:
The penetration of the carbon steel pipe and equipment wall by pits is a process that consists of three stages:
- Formation of the surface layer on steel surface,
- Initiation of pits at localized regions on the steel surface where surface layers break down
- Pit propagation and eventual penetration of the wall.
Classical models, developed for corrosion-resistant alloys, assume surface layers (commonly known as passive layers) are inherent to the metals/alloys. Nonclassical models seamless pipe manufacturers develop for carbon steels assume that the surface layers form in that place once the carbon steels are put in the environment.
Wrapping it up:
Some applications require close, smooth surfaces and tolerances that necessitate the requirement of cold-drawn tubes. For example, you can notice an extensive application of cold-drawn carbon steel seamless tubes and pipes in heat exchangers, bearing, and automotive sectors.
The leading pipe manufacturers offer the highest quality cold-drawn seamless tubes abiding by international regulations. Hence, you can use these pipes for their finesse, durability, corrosion resistance, and dimensional accuracy. Selecting high-quality components always is the key to the success of any business or industry.
If you are opting for carbon cold-drawn seamless steel tubes, you must learn about the features and benefits of this product in detail. If you are reading this part, it means that you have completed the article, which means you now have a clear idea about what you can expect from cold-drawn carbon steel tubes.
However, to ensure that you get high-quality pipes, you should get in touch with a reputable seamless pipe manufacturer who has experience in producing carbon steel pipes by maintaining international standards.
