Stainless steel has become the world's most widely used and popular material since its invention over a century ago. Its corrosion resistance is due to its chromium content. Resistance can be demonstrated in reducing acids as well as in chloride solutions against pitting attacks. It requires little maintenance and has a familiar shine, making it an excellent and superior material for stainless steel pipes. Stainless steel pipe is offered in a variety of product types, including welded pipes and seamless pipes. Because the composition can change, it can be used in a variety of industries. Many industrial companies use stainless steel pipes on a regular basis. In this blog post, various types of stainless steel pipes will be discussed in terms of manufacturing methods and standards. In addition, this blog post discusses the various applications of stainless steel pipes in various industries.

Various Stainless Steel Pipe Types Based on Production Method

The method of producing welded pipes from a continuous coil or plate involves rolling the plate or coil in a circular section using a roller or bending equipment. The filler material is suitable for large-scale production. Welded pipes are less expensive than seamless pipes, which have a higher overall production cost. Although these production methods, specifically welding methods, are critical components of stainless steel pipes, the specifics of these welding methods will not be discussed. It could be a topic of another blog post of ours. However, welding methods for stainless steel pipes are frequently abbreviated. It is critical that you are familiar with these abbreviations. There are several welded techniques, for example:
•    EFW stands for electric fusion welding.
•    ERW (Electronic Resistance Welding)
•    HFW stands for high-frequency welding.
•    SAW stands for submerged arc welding (spiral seam or long seam)
In the market, there are also seamless stainless steel pipes. More specifically, after the production of electric resistance welding, metal is rolled along its length. Metal extrusion can produce seamless pipes of any length. ERW pipes have welded joints that run the length of the pipe, whereas seamless pipes have joints that run the length of the pipe. There is no welding in seamless pipes because the entire manufacturing process is done with a solid round billet. The seamless pipes were finished to the wall thickness and dimensional specifications in various diameters. These pipes are used in high-pressure applications such as oil and gas transportation, industries, and refineries because there is no seam on the body of the pipe.

Types of Stainless Steel Pipes Based on Alloy Grades

Steel's overall chemical composition has a significant impact on end-product mechanical properties and application areas. As a result, it is not surprising that they can be classified based on their chemical compositions. However, when attempting to determine the grade of a specific stainless steel pipe, various nomenclatures may be encountered. The most commonly used standards for identifying steel pipes are DIN (German), EN, and ASTM grades. One can consult a cross-reference table to find equivalent grades. The table below provides an overview of these various standards.

DIN Grades    EN Grades    ASTM Grades
1.4541    X6CrNiTi18-10    A 312 Grade TP321
1.4571    X6CrNiMoTi17-12-2    A 312 Grade TP316Ti
1.4301    X5CrNi18-10    A 312 Grade TP304
1.4306    X2CrNi19-11    A 312 Grade TP304L
1.4307    X2CrNi18-9    A 312 Grade TP304L
1.4401    X5CrNiMo17-12-2    A 312 Grade TP316
1.4404    X2CrNiMo17-13-2    A 312 Grade TP316L

Different Types Based on ASTM Specifications

It is a well-known fact that industry and standards are inextricably linked. Because of differences in various organization standards for a wide range of application ranges, the manufacturing and testing results may differ. The buyer must first grasp the fundamentals of various industrial specifications for their projects, before actually doing the purchasing operations. It is also an appropriate phrase for stainless steel pipes.
The American Society for Testing and Materials is abbreviated as ASTM. ASTM International develops service standards and industrial materials for a variety of industries. This organization has currently served over 12000 standards used in businesses all over the world. Over 100 standards apply to stainless steel pipes and fittings. Unlike other standard organizations, ASTM covers almost all types of pipes. For example, as American pipe items, the entire range of pipes is available. For high-temperature services, seamless carbon pipes with appropriate specifications are used. The ASTM standards are defined by the chemical composition and specific manufacturing processes associated with the material. As examples, some ASTM material standards are provided below.
• A106 - For high-temperature applications
• A335 - Ferritic steel seamless pipe (For high temperature)
• A333 - Alloy steel seamless and welded pipes (For low temperature)
• A312 - Cold worked welded, straight seam welded, and seamless pipes are used for general corrosive service and high-temperature service.

Various Stainless Steel Pipes Based on Application Areas

Sanitary Pipes: Stainless steel sanitary pipes are used in high sanitation applications such as sensitive applications. In the industry, this pipe type is given the highest priority for efficient fluid flow. Because of its ease of maintenance, the pipe has the best corrosion resistance and does not rust. Depending on the application, different tolerance limits are established. Sanitary pipes of the ASTMA270 grade are widely used.
Mechanical Pipes: In mechanical pipe applications, hollow components, bearing parts, and cylinder parts are commonly used. The mechanics can be easily adapted to a wide variety of sectional shapes, including rectangular, square, and other shapes that add up to conventional or traditional shapes. In mechanical applications, the most commonly used grade types are A554 and ASTMA 511. They are extremely Machinable and are used in applications such as automotive and agricultural machinery.
Polished Pipes: Depending on the specifications, polished stainless steel pipes are used in the home facility. Polished pipes help to reduce wear and tear on working components. It also helps to reduce adhesion and contamination on different equipment surfaces. The electro-polished surface has numerous applications. Stainless steel polished pipes do not need any additional coating. Polished pipes play an important role in aesthetic and architectural applications.
Based on various criteria, these are some different types of stainless steel pipes. This blog article does not provide detailed information about manufacturing methods or the properties of various grades. These two concepts should also be understood. These two ideas, however, will have to wait for another blog post.