Tubes and pipes: Most people use these terms interchangeably, but there are some key differences you need to consider before placing an order.
This article will explore the differences between tubes and pipes, including:
- Applications
- Sizing
- Cost
- How to order
In short, the main differences come down to application, sizing standards, and how they’re manufactured.
Where are tubes and pipes used?
Pipes are generally for transporting fluids and gases from one place to another in a larger system. Think plumbing, chemical processing, and oil and gas pipelines.
Tubes are more often used for structural support or in applications that demand exact measurements. They’re common in medical devices, heat exchangers, and measurement instruments.
Knowing these applications is key to understanding the difference between tubes and pipes.
Sizing: Understanding the Dimensional Differences
Tubes and pipes also differ in the way they’re sized. Here’s a look at the key differences:
Outside Diameter (OD)
Tubes are specified by their exact outside diameter, and the number you see listed is usually very close to the actual measurement. The tolerances are usually pretty tight.
Pipes, on the other hand, are specified by a “Nominal Pipe Size” or NPS. For smaller pipes, the NPS doesn’t directly correspond to the outside diameter. It’s more of a category than an exact measurement.
For pipes 14″ and larger, the NPS does match the OD.
One exception to the “exact measurement” rule is copper tubing, which often has an OD that’s 1/8″ larger than the stated OD.
Wall Thickness and Pipe Schedule
Tube wall thickness is measured in inches or gauge, giving you a direct measurement of the material’s thickness.
Pipe wall thickness is indicated by a “schedule” number like Schedule 40 or Schedule 80. These numbers relate to the pipe’s ability to withstand pressure. Higher schedule numbers mean thicker walls and a higher pressure rating.
Cost and Manufacturing
Tubes usually cost more than pipes.
This is because tubes require more precise manufacturing. They need to be constructed to very strict outside diameter (OD) tolerances.
Manufacturers must use careful monitoring and quality control to make tubes.
Pipe manufacturing, on the other hand, focuses on making products that efficiently transport fluids. The goal isn’t usually precision.
How to Order
It’s important to use the right terminology when ordering tubes and pipes. Otherwise, you might end up with the wrong materials.
To order tubes, you need to specify the outside diameter (OD) and the wall thickness. For example, you might say, “I need 1/2″ OD x 0.065″ wall thickness stainless steel tubing.”
To order pipes, you need to specify the nominal pipe size (NPS) and the schedule. For example, you might say, “I need 3″ NPS Schedule 40 steel pipe.”
Common Misconceptions and Key Takeaways
It’s a common mistake to assume that Nominal Pipe Size (NPS) is the same as the inside diameter (ID). While NPS was meant to approximate the ID, that’s often not true, particularly for smaller sizes.
Remember, choosing between tubes and pipes depends on what you’re going to use them for.
Finally, be careful to note the differences in how they’re sized and how you should order them.
Frequently Asked Questions
Why is tubing better than piping?
Whether tubing is “better” than piping depends entirely on the application. Tubing is generally preferred for applications requiring flexibility, tighter bends, and precise control of flow. Piping is better for structural applications, high-pressure environments, and larger-scale fluid transport. It’s about choosing the right material for the job.
What is the difference between a tube and a hose?
While both are used for fluid transfer, hoses are designed for flexibility and are often reinforced with layers of fabric or other materials. Tubing, on the other hand, is typically more rigid and precise in its dimensions. Hoses are often used for temporary or mobile applications, while tubing is used more in fixed systems.
Is pipe as strong as tube?
Generally, yes, pipe is stronger than tube, especially when comparing the same material and wall thickness. Pipes are designed to withstand higher pressures and loads, making them suitable for structural applications and transporting fluids over long distances. However, specialized, high-strength tubing can rival the strength of some pipes.
What is the difference between a tube and a pipe?
The key difference lies in how they’re measured and their typical uses. Pipe is measured by its inner diameter (ID), while tubing is measured by its outer diameter (OD). Pipes are primarily used for transporting fluids and gases, while tubing is more commonly used in structural applications, instrumentation, and smaller-scale fluid systems. Think of pipes as highways for fluids, and tubes as the smaller, more precise routes.
Key Takeaways
Tubes and pipes differ in manufacturing, sizing, application, and cost. Knowing these differences is crucial to choosing the right material.
When ordering, be sure to understand the application, sizing conventions, and other required information. When in doubt, consult with experts who can help you navigate the selection process.