You might be familiar with carbon steel pipes. They are strong and versatile, with numerous applications in various industries. Several key considerations are critical before a manufacturer chooses a carbon steel pipe. One such consideration is the pipe schedule. Schedule is a standardized method of describing the wall thickness of pipes. Commonly seen schedules are 10, 40, 80, 120, and 160. As you may notice, schedule 80 lies at the very middle of this spectrum. Therefore, it is a crucial category of carbon steel pipes.
Schedule 80 Carbon Steel Pipe
Schedule 80 carbon steel pipes are highly desirable for their durability and pressure rating. Their counterpart, Schedule 40, is excellent for standard plumbing but fails at heavy-duty operations.
Schedule 80 carbon steel is characterized by its heavier walls and strong tempering properties. As a direct result, it can withstand more demanding conditions. They are composed primarily of iron and carbon, with manufacturing specifications according to the Schedule 80 standard. Both schedule and NPS are key piping terminologies. They are employed by North American bodies, namely, ANSI, ASME, API, and ASTM. They are globally accepted categories of pipes.
Schedule 80 Carbon Steel Pipe Chart
| Nominal Size (inches) |
Outside Diameter (inches) |
Outside Diameter (mm) |
Wall Thickness (inches) |
Wall Thickness (mm) |
Weight (lb/ft) |
Weight (kg/m) |
|---|---|---|---|---|---|---|
| 1/8 | 0.405 | 10.3 | 0.095 | 2.41 | 0.31 | 0.47 |
| 1/4 | 0.54 | 13.7 | 0.119 | 3.02 | 0.54 | 0.8 |
| 1/2 | 0.84 | 21.3 | 0.147 | 3.73 | 1.09 | 1.62 |
| 3/4 | 1.05 | 26.7 | 0.154 | 3.91 | 1.47 | 2.2 |
| 1 | 1.315 | 33.4 | 0.179 | 4.55 | 2.17 | 3.24 |
| 1 ¼ | 1.66 | 42.2 | 0.191 | 4.85 | 3 | 4.47 |
| 1 ½ | 1.9 | 48.3 | 0.2 | 5.08 | 3.63 | 5.41 |
| 2 | 2.375 | 60.3 | 0.218 | 5.54 | 5.02 | 7.48 |
| 2 ½ | 2.875 | 73 | 0.276 | 7.01 | 7.66 | 11.41 |
| 3 | 3.5 | 88.9 | 0.3 | 7.62 | 10.25 | 15.27 |
| 3 ½ | 4 | 101.6 | 0.318 | 8.08 | 12.5 | 18.63 |
| 4 | 4.5 | 114.3 | 0.337 | 8.56 | 14.98 | 22.32 |
| 5 | 5.563 | 141.3 | 0.375 | 9.53 | 20.78 | 30.97 |
| 6 | 6.625 | 168.3 | 0.432 | 10.97 | 28.57 | 42.56 |
| 8 | 8.625 | 219.1 | 0.5 | 12.7 | 43.39 | 64.64 |
| 10 | 10.75 | 273 | 0.594 | 15.09 | 64.43 | 96.01 |
| 12 | 12.75 | 323.8 | 0.688 | 17.48 | 88.63 | 132.08 |
| 14 | 14 | 355.6 | 0.75 | 19.05 | 106.13 | 158.1 |
| 16 | 16 | 406.4 | 0.844 | 21.44 | 136.61 | 203.53 |
| 18 | 18 | 457 | 0.938 | 23.83 | 170.92 | 254.55 |
| 20 | 20 | 508 | 1.031 | 26.19 | 208.87 | 311.17 |
| 24 | 24 | 610 | 1.125 | 30.96 | 296.58 | 442.08 |
Schedule 80 and Its Importance
Schedule 80 pipes combine the best aspects of mild and high-carbon steel pipes. It is of critical importance in construction projects. As they are seamless steel pipes, they form the basis of several building structures and sub-structures. Engineers prefer to schedule 80 pipes for their high tensile and yield strength. It is essential to note that in structural engineering tasks, pipe specifications are a primary consideration. Even a minute miscalculation can result in unexpected deviations from the architectural plan. Therefore, civil engineers consult the pipe specification chart according to their requirements. As we mentioned before, the pipe schedule is not a measured value. In fact, it is often combined with NPS to accurately determine dimensions. Pipe specification charts enable professionals to do this. Pipe Schedule and NPS allow workers to accurately determine parameters such as outside diameter, wall thickness, and weight.
Differences Between Schedule 40 and Schedule 80
While different in specifications, both schedule 40 and 80 have some overlapping applications. For example, both pipes are used in construction. However, schedule 40 is preferred for lightweight structures and interior piping. The fundamental difference between the pipes is thickness. Schedule 40 pipes have a lesser wall thickness than schedule 80 pipes. In addition to carbon steel, you may also find schedule 40 stainless steel pipes. They have a singular advantage in availability and cost-effectiveness. It results from a lower procurement price as compared to Schedule 80. However, due to their higher-pressure rating, Schedule 80 pipes are particularly suitable for heavy-duty applications. They are superior for projects involving high-pressure gases, chemical processing, or power generation. Due to higher wall thickness, they have greater tensile and yield strength than schedule 40 pipes. Click here to see more differences between SCH40 and SCH80.
Ways of Representing Schedule 80 Pipes
You will benefit from knowing some standard representations of schedule 80 pipes. Pipes that are fit for general-purpose applications are often termed as STD. These are standard weighted pipes. They possess an inner diameter of DN250mm. Schedule 80 pipes are also referred to as thick-walled pipes. They are often represented as XS. Their inner diameter falls inside DN200mm. Going above schedule 80 to 120, we have extra-thickened pipes. They are shown as XXS. Their inner diameter falls inside DN250mm.
Conclusion
By familiarizing yourself with pipe schedule systems, you gain control over your piping project. The first step of executing a successful project is to be familiar with the tools. Carbon steel pipes have a wide variety of standardized models. This is in part due to their widespread use and versatility. Choosing a pipe schedule is the most fundamental decision you will make. With the knowledge from this article, you know how it relates to a pipe’s overall specifications. If you have any further questions regarding pipe schedules, please reach out to us. Our professional team is eager to help you make the right decision.