Double Extra Strong

Double Extra Strong, abbreviated as XXS, also called double extra heavy (XXH), or extra extra heavy (XXH), is another classification used for certain types of pipe thickness and pressure ratings, particularly in the context of steel pipes used in industrial applications.  It is a designation that indicates an even thicker pipe wall compared to the "Extra Strong" (XS), and it's capable of withstanding higher pressure levels.

Like the XS designation, XXS is a part of the pipe schedule system defined by organizations such as the American National Standards Institute (ANSI) and the American Society of Mechanical Engineers (ASME).  The schedule system provides guidelines for different pipe wall thicknesses and pressure ratings based on specific applications.

In the ASME B36.10 and ASME B36.19 standards, the XXS designation corresponds to an even higher wall thickness and pressure rating than the XS designation.  XXS pipes are commonly used in applications where extremely high pressures or harsh conditions are encountered, such as in certain parts of the petrochemical, oil and gas, and power industries.  It's important to note that the terminology and classification might differ slightly in different regions or industries.  Additionally, the exact dimensions, wall thickness, and pressure ratings associated with XXS pipes can vary depending on the material, industry standards, and specific application.

When specifying pipes for industrial applications, it's crucial to consult the relevant standards, engineering specifications, and industry guidelines to select the appropriate pipe schedule and thickness to ensure the desired performance, safety, and longevit.