Thermal Expansion in Piping

The Space-Ring System (SRS) Allows for Thermal Expansion

Generally, industrial assets like piping will expand when heated, and contract when cooled.


Thermal Expansion in Piping

As piping heats up, changes in its shape, volume and area occur naturally.  This is because of thermal expansion.

As the temperature of the pipe changes from its offline temperature to its operating temperature, its diameter will increase.  This is caused by the molecular structure expanding because of an increase in kinetic energy due to the higher operating temperature.  At this increased temperature molecules move around more, causing expansion.

The amount of expansion divided by the change in temperature is called the material’s coefficient of thermal expansion.

Thermal expansion coefficient

When pipes cool, they begin to contract, causing their shape to change once again.  The lower temperature means molecules move around less, causing contraction.

Some pipes maybe flexible enough to absorb the thermal expansion without causing excessive force or stress, or significant damage.  However, most are not, this is where major problems will occur.


Thermal Expansion using End Caps

As a pipe heats up, it naturally increases in diameter due to thermal expansion.  The rigid shape / material properties of end caps don’t allow for any movement or expansion.  This causes the end cap to damage the pipe itself as its diameter increases.  Eroding any coatings system and encouraging localised corrosion – bringing the integrity of the pipe into question.

If the underlying pipe and end cap materials are dissimilar then, with the introduction of moisture, this will allow galvanic corrosion to occur.

In addition, as the pipe begins to cool, causing contraction, the end caps can become loose due to a lack of flexibility.


End cap cladding system


Thermal Expansion using the Space-Ring System (SRS)

The SRS uses support rings which are held in place by silicone capped bolts.  These silicone caps allow for movement and act as a heat break.  So as the diameter of the pipe increases the SRS allows for thermal expansion.

In comparison to end caps, the SRS has no sharp edges, meaning no damage will occur to any applied coatings system.  In turn the coating system isn’t eroded, resulting in no direct metal to metal contact, meaning galvanic corrosion cannot occur.

Also, as the pipe begins to cool and contract, the allowance for thermal expansion means the support rings stay securely in place.


The Space-Ring System, cladding support


For more on how the Space-Ring System can protect your assets >>

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