Stainless Steel Pipe vs Instrumentation Tubing

Comparing these two popular products to help you find the ideal solution for your piping process or application

While you might see pipe and tube used interchangeably when talking about stainless steel products, they’re actually different items -- both in terms of how they’re described and their common uses.

In this guide, we’re going to look at critical considerations -- such as sizing, product shapes, and typical usage -- when determining the best stainless steel pipe or instrument tubing for your projects.

Pipes and Tubes: What’s the Difference?

At first glance, pipes and tubes are both cylindrical hollow metal objects used in piping processes to move various materials from one point to another. But there’s more to it than that.

Uses for Instrument Tubing and Stainless Steel Pipes

Piping is designed to move and route the flow of liquids, gasses, and other materials between holding areas, processing areas, and other parts of the intended process.

Instrument tubing is often used alongside these piping systems, allowing the integration of pressure gauges, pressure switches, valves, flow monitors, and other critical instrumentation to assist with safety, automation, and other aspects of piping system operations.

Sizing Pipes and Tubes

For pipes, the most critical measurements are the nominal pipe size (NPS) and wall thickness (also known as the schedule). /a>

For example, NPS 4 pipe actually has an outside diameter of 4.5-inches (114.3mm).

When pipe is equal to or greater than 14" NPS, the size (14" in this case) then indicates the outside diameter.

In contrast, tubing sizing typically focuses on outer diameter (OD) and wall thickness. So, 4-inch tubing has an OD of exactly 4-inches.

This is because pipe sizing often determines overall capacity and volumes while instrumental tubing typically has other considerations such as pressure ratings.

As such, tubing sizes are also more precise and typically require greater quality assurance and tighter tolerances than piping.

Pipe and Instrument Tube Designs

Due to their smaller sizes, manufacturers can bundle tubes to create a single unit with multiple tube paths.

Parker Hannifin’s “Parflex” heat trace tubing products are a great example of this.

By combining multiple tubes into a single bundle, you can greatly reduce complexity over long runs and minimize cable tray space requirements.

This approach also reduces stress and potential damage of elements during installation routing.

Pipe and Tube End Connections

In most cases, pipes will use either bevelled, threaded, or plain ends.

Tubes are typically cut to length with tube cutters, then deburred for safety and flow reasons.

This allows quick connection fittings and valves with greater compatibility with a range of instrumentation components.

Manufacturing Pipes and Tubes

All tubes will undergo dimensional quality checks for straightness, roundness, wall thickness, and surfaces during manufacturing.

While pipes are still subject to a strict tolerance, the ability to mass produce most common pipe sizes and types allows for bulk orders and faster delivery.

Due to high volumes, pipes are often produced on a continuous basis for distribution around the world.

If you’re looking for tubing for your next project, be sure to plan for required production and delivery times to avoid unexpected surprises.

Packaging of Pipes and Tubes

Most pipes are bundled and secured for shipment, whereas tube is often packaged in cardboard tubes for bulk delivery due to their size. 

However, as instrumentation tubing is often produced in much smaller diameters, coils and rolls are often used to allow for more compact storage and easier transport.


While pipe and instrumentation tubes might look similar at a glance, they are different in many ways.

  • Sizing is approached differently for both product types. Understanding exactly what you need is critical for optimizing spending and proper installation.

  • As tubing is subject to stricter requirements and lower-volume manufacturing processes, it is often more expensive than mass-produced piping when compared by weight.

As a leading provider of piping and tubing products in Canada, Unified Alloys’ extensive selection of instrumentation tube products and stainless steel pipe products can help industries source the ideal components to keep their piping systems running smoothly -- even in the harshest environments. Our expert sales analysts have experience with a range of industries to help you understand the critical considerations when choosing components for your next design or when maintaining existing systems. Call today to find out how we can help you.


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