Comparison of Pipe and Tube (Pipe Vs Tube)

What is a Pipe?

Pipes are used for transporting fluids and gases in Chemical, Petrochemical, Power Plants, Refineries, Storage units, compressed air systems, plumbing systems, etc. They are circular in cross-section and specified by Nominal Pipe Size.

What is a Tube?

Tubes are used for mechanical applications (Heat Exchanger, Fired heater, Boiler, etc.), for instrumentation systems (used for measuring instruments); for structural applications, etc and could be rigid or flexible. They are specified by their outer diameter and tube wall thickness, in inches or in millimeters.

Differences between Pipe and Tube

From a layman’s viewpoint, Both Pipe and Tube seem to be the same as they have many similarities like both are hollow, made from metals, both can transfer fluids, etc. Many a time, these terms are used interchangeably. But in actual practice Tubes and Pipes are not the same as both possess different features. Through this article, we will try to investigate all such characteristics based on a few parameters like Size, Shape, Diameter, Thickness, Use, Availability, End Connection, Design Standard, etc.

Sr NoParameterPipe CharacteristicsTube Characteristics
1ShapeAlways cylindrical or round in shapeIn general, cylindrical. However, different other shapes like square, rectangular, etc. are available.
2SizePipe is Specified by Nominal Pipe Size (NPS) or Nominal Bore (NB).The size of Tubes are specified in millimeter or in inches by outside diameter.
3DiameterThe outside diameter of pipe up to size 12” are numerically larger than corresponding pipe sizeOutside diameter of tubes is numerically equal to the corresponding size.
4ThicknessPipe Wall thickness is expressed in schedule number that can be converted into mm or inches.Tube Wall thickness is expressed in millimeter, or inches, or BWG (Birmingham wire gauge.)
5Thickness IncrementPipe thickness depends on the schedule, so there is no fixed incrementThe thickness of tubes increases in standard increments such as 1 mm or 2 mm
Pipe vs Tube
Difference Between Pipe and Tube
Sr NoParameterPipe CharacteristicsTube Characteristics
6ApplicationUsed in all Process, Power & Utility lines to carry fluids.Generally used in tracing lines, tubes for heat exchanger & fired heater & in instrument connection. They are more prevalent in medical area, construction, structural or load bearing.
7AvailabilityAvailable as the small bore and the big boreNormally small-bore tube is used in process piping. For structural use, tubes are available in custom sizes.
8Structural RigidityAlways rigid and resistant to bendingAvailable as rigid as well as flexible depending on the application. Rigid tubes are normally used in structural applications whereas copper and brass tubes can be flexible.
9Joining and StabilityJoining pipes is more labour intensive as it requires flanges, welding, threading, etc.Tubes can be joined quickly and easily with flaring, brazing or couplings, but for this reason, they don’t offer the same stability
10TolerancePipe tolerances are not too restrictive.Tolerances are very strict with tubes compared to pipes and tubes are often more expensive to produce than pipes
Pipes used in operating process plant
Pipes used in operating process plant
Sr NoParameterPipe CharacteristicsTube Characteristics
11ManufacturingPipe manufacturing is easier as compared to tubesTubes need cumbersome tests, inspection and quality control than pipes.
12CostCheaperCostlier
13Packing & DeliveryDelivered in bundle as bulk item. Delivery time is short.Tubes are usually wrapped with wooden box or thin film and delivered with much care. Delivery time is longer.
14Production QuantityProduced in mass quantity and for long distance applications.Produced in small quantity depending on requirement.
Tubes used inside a Fired Heater
Tubes used inside a Fired Heater
Sr NoParametersPipe CharacteristicsTube Characteristics
15End ConnectionNormally plain or bevelled for welding purposesWith coupling ends, irregular ends, special screw thread etc.
16Surface FinishInner and Outer surface is rough with comparison to tubeNormally, both inner and outer surface are smooth
17Common materialCarbon SteelAlloy Steel
18Design Codes & StandardsThickness is decided as per governing codes like ASME B 31.3/ B31.1/ B 31.4/ B31.8 or IBR CodesDepending on use thickness is decided.

I am sure there will be many more differences, I invite the readers to list out those in the comments section.

Few more useful resources for you.

Difference between Tee and Barred Tee
Comparison between Piping and Pipeline Engineering
Difference between Stub-in and Stub-on Piping Connection
Difference between Centrifugal and Reciprocating Compressor
Differences between Hot-dipped galvanization and Electro-galvanization
CAESAR II vs START-PROF Piping Stress Analysis Software Comparison
API vs ANSI Pump

Anup Kumar Dey

I am a Mechanical Engineer turned into a Piping Engineer. Currently, I work in a reputed MNC as a Senior Piping Stress Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world.

4 thoughts on “Comparison of Pipe and Tube (Pipe Vs Tube)

  1. Hi, very useful & detail difference has given between tube & pipe. It’s really helpful, which added few new point in knowledge.
    Thanks

  2. Dear Anup thanks, I am Noor ul Arefeen from Pakistan. Your above subject is very informative and you have tried to contain very big topic in short spain. I am running my own business in mechanical fabricaion. I will keep in touch with for further knowledge. Thanks once again.

  3. HI ANUP SIR,
    IAM ALSO A MECHANICAL ENGINEER GRADUATE AND WORKING AS PROCESS DESIGNER. AND I HAVE ALSO INTEREST TO BECOME A PIPING ENGINEER, CAN YOU PLEASE SUGGEST HOW I BECOME THE PIPING ENGINEER.
    AND YOURS ARTICLES ALSO VERY USEFUL TO GAIN THE KNOWLEDGE ABOUT THIS FIELD THANK YOU VERY MUCH

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