# Pipe diameter expansion due to temperature increase

• doop4
In summary, the conversation is about calculating the increase in diameter and wall thickness of a 60mm OD stainless steel pipe as the temperature of water within the pipe increases by 10 deg C. The coefficient of thermal expansion and length of the pipe are factors in the calculation, causing confusion for the person seeking help. A recommended resource for further understanding is provided.

#### doop4

Hi

Firstly, this is not a homework problem. It's regarding some flow experimental results I have and to understand the results further I am trying to identify possible reasons for the patterns I see. I don't have expertise in thermodynamics hence finding the following problem a bit puzzling. Any help and pointers would be most appreciated.

I have a 60mm OD stainless steel pipe with a wall thickness of 2.5mm I'd like to calculate the increase in both these values as the temperature of water within the pipe increases by 10 deg C. The straight length of the pipe is 4m and it is part of a complicated flow loop so therefore some approximations will need to be made.

How would I go about calculating the increase in the pipe OD and wall thickness as a result this change in temperature? Thanks in advance for your help!

It is a straightforward calculation multiplying coefficent of thermal expansion by length (of whatever dimension) and temperature change. Give it a try and we'll check your answers...

russ_watters said:
It is a straightforward calculation multiplying coefficent of thermal expansion by length (of whatever dimension) and temperature change. Give it a try and we'll check your answers...

Thanks for your reply! Why should the length of the pipe matter when I am after the expansion in diameter of the pipe? Did you mean diameter instead of length? Puzzled but I'll have a go assuming that you meant to say diameter. Forgive me for being dim! :(

thermal expansion=6.5e-6 (for stainless steel)
temp change= 50F
D=60mm (0.197ft)

So

expansion= 6.5e-6 x 0.197 x 50= 0.06ft ~ 18mm?

That sounds horribly wrong. I think I've misunderstood what you've said. Any help will be much appreciated!

P.S: Could you recommend a reputable book which has changes in pipe diameter as a result of varying temperature?

doop4 said:
Why should the length of the pipe matter when I am after the expansion in diameter of the pipe? Did you mean diameter instead of length?

The diameter is also a length (as is the radius, wall thickness, etc.). They all have units of distance, and they'll all expand linearly with temperature if unconstrained. It's just a confusing part of the terminology that the word is the same as the word that describes the distance of the longest extent of the pipe (the pipe length).

doop4 said:
expansion= 6.5e-6 x 0.197 x 50= 0.06ft ~ 18mm?

Whoa, check your calculations. How can multiplying a number in the parts per million by ten give you 0.06?

doop4 said:
P.S: Could you recommend a reputable book which has changes in pipe diameter as a result of varying temperature?

It's not a book, but http://www.engineeringtoolbox.com/thermal-expansion-pipes-d_283.html" [Broken] might get you started.

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## What is pipe diameter expansion due to temperature increase?

Pipe diameter expansion due to temperature increase is a phenomenon where the diameter of a pipe increases as the temperature of the pipe increases. This is because as the temperature increases, the molecules in the pipe vibrate more, causing the pipe to expand.

## Why does pipe diameter expand when temperature increases?

This is due to the thermal expansion coefficient of the material the pipe is made of. The thermal expansion coefficient is a measure of how much a material expands or contracts when its temperature changes. When the temperature of the pipe increases, the material expands, causing the diameter to increase.

## How does pipe diameter expansion affect the flow of liquid or gas?

Pipe diameter expansion can affect the flow of liquid or gas by changing the pressure and velocity of the fluid. When the pipe expands, the volume inside the pipe increases, which can lead to a decrease in pressure and an increase in fluid velocity. This can also cause changes in flow rate and turbulence in the pipe.

## What factors influence pipe diameter expansion due to temperature increase?

Some factors that can influence pipe diameter expansion include the material and composition of the pipe, the temperature change, and the length and diameter of the pipe. Other factors such as the surrounding environment, pressure, and fluid flow can also play a role.

## How can pipe diameter expansion be accounted for in engineering designs?

In engineering designs, pipe diameter expansion can be accounted for by using the thermal expansion coefficient of the material and calculating the expected change in diameter based on the temperature change. This can be incorporated into the design to ensure the pipe can accommodate the expansion without causing issues such as leaks or structural damage.