Awareness of how an Heat Exchanger failure occurs due to various leaks, Ruptures, and Tube chocking. These data is been taken from practical exposure that have occurred in some of the industries and most commonly occurred failure.
1. Course: Heat Exchanger, Inspection, Condition Assessment, Fitness for Service, Failure
Investigation, NDT
Plant shutdown time due to
Heat Exchanger failures – Leaks, Ruptures and
Tube choking (Explained)
Heat transfers and liquid management frameworks are most critical operations for reaction
kinetics as well as waste heat recovery systems for any industry including the Fertilizers,
Petrochemicals, Refinery, Oil & Gas. A heat exchanger should be a system that adequately
and efficiently takes the heat from one medium and exchange to another; without the fluids
getting mixed. More often than not, it is all about the media (liquid or gases) that pass
through isolated chambers; wherein the walls of such systems act as an essential heat
transfer element with the greatest degree of efficiency. The operation and continual running
of Heat Exchanger therefore, makes inspection jobs critical. Heat Exchanger has got to be all
the way functioning. It’s necessary too!
Herein, when it comes to Heat Exchangers, there are still severe as well as critical failures
that lead production units go in huge trouble. In fact, it directly impacts the operation and
proper functioning of Heat Exchangers, leading to operations shut-down or poor-quality
controls. That’s what can make or break the deal in such industries without a doubt!
So, you might be wondering what causes a heat exchanger go failure? Hence, the situations
that create turmoil are mostly associated with temperature fluctuations, fouling, cracks,
punctures, ageing and material fatigue. Therefore, it’s important you understand the factors
making heat exchanger non-operative and slowing down operations in your industry by far.
Questions are – How do you make your heat exchanger unstoppable? What do you check
very often in its operation and functioning? What are the parameters you check through to
determine how successful it is into your industry? Do comment and let us know for sure!
With that being said – We will discuss factors that cause any heat exchanger non-operative.
So, take them into your consideration for further reference and understanding. Time to get
started!
Let’s List Main Reasons Behind Heat Exchanger Failures:
2. 1) Temperature Changes:
Without a doubt – Temperature variation makes the difference. This is one of the reasons as
to why Heat Exchangers become non-operative at the same time. So, can we say – It’s more
likely because of the continuous rise and fall in the temperature? Well, yes! It’s true.
Temperature changes hugely impact the performance and stopping it further from
functioning. Change in temperature profiles along the heat exchanging surface areas is
related to load changes in the plant. There are conditions in which the thin metal sections
of heat exchangers encounter consistent expansion and contractions by far, due to change
of temperature profiles. Needless to say – such changes are inescapable and may lead to
failure of heat exchanger in some period of its life. Resultant leakages of exchangers,
particularly in lethal services, are of great concerns that endanger human and environmental
safety. Therefore, if you are considering the main reasons why heat exchanger fails;
deliberate temperature changes one of them in the same regards.
2) Cracks:
It’s not unusual and often fatal. Because of the impacts of extreme thermal cycling, surface
breaks more often. That mainly occurs on Tube Sheet. Thermal cycling here is related more
with the number of startup and shutdowns of exchanger, although also relates to frequent
load changes. So, it’s certain a point to consider when it happens? Well, the answer is – The
situation in which the Tube and Tube Sheet are welded together at the same time. Such
circumferential splits make heat exchanger to drop and make uncommon thermal stress
inducements across the welded / expanded joints between the tubes and tube sheet.
Therefore, a crack in heat exchanger is also a factor behind its failure!
3) Fouling and corrosion:
Have you ever been in the situation to figure out what happens when fouling occurs on any
heat exchanger? The conditions become severe, if not handled or checked properly. Thus,
when it comes to deposition of any undesired material on heat exchanger surface, that’s
what it is called fouling. Some of the other ways out, it affects the functioning of heat
exchanger. Moreover, fouling happens to also affect the efficiency of heat exchangers by far.
That is the reason – its maintenance is given great importance and significance. Fouling
brings the thermal obstruction and lowers down the heat transfer coefficient of any heat
exchanger in an unlikely manner. So, it’s fair enough to state – Fouling likewise blocks liquid
3. stream, quickens erosion, results in under deposit corrosion and builds pressure drop
crosswise over heat exchangers to making them further stop working to the greatest degree
possible.
4) Age:
Again, it’s important to check over if your heat exchanger is aging by the time it puts things
to stop. We understand – essentially hot temperatures highly impact metallurgical properties
of metals and alloys! Few of the such time dependent damage mechanisms are - Carbon
steel in wet H2S service leading to hydrogen embrittlement, Alloy steels (0.5 Cr – 9 Cr)
above 593°C undergoing carburization, 2.25 Cr-1 Mo above 399°C suffer temper
embrittlement, Austenitic stainless steel above 593°C damage by sigma phase formation,
and so on. In such situation, things may go wrong with your Heat Exchanger. Though, they
are made or designed in such a way to withstand extreme temperatures; however, the age is
also a factor that can never be put off at the backstage! That’s what makes it further fall flat
and non-operative! In the worst-case scenario – Consistent expansion and contractions also
lead the heat exchanger getting exhausted and little splits take a room, making it a typical
issue that ends up failing over the period of time!
5) Material Fatigue:
Material fatigue crucially impacts the functioning of any heat exchanger. In fact, it lowers the
performance and the operations come to standstill. So, what is Material Fatigue when we
discuss about heat exchangers? Here we go – With the passage of time, it’s certain to share
there are materials as well as components experience cracking especially influenced by the
process induced vibrations in tubes. That’s the reason – Certain weaknesses inside the heat
exchangers start to occur. Heat exchanger comes to a dead end and stop working! It’s just
the auxiliary damage of a material brought about by continued stacking: Thermal and
Mechanical Burdens which leads to breaks and holes too!
Here Is Why Regular Heat Exchanger Inspection Checklist Is
Important:
Well, are you considering keeping an eye over your Heat Exchanger? Are you sure what you
are up with your Heat Exchanger? Is everything going good? If not, do stick since
performing important and crucial Heat Exchanger Inspection is one of the best as well as
4. mandatory steps one would ever look for. So, some of the tests to go through and take
note of are!
Visual Inspection
Eddy current test
IRIS (internal rotary ultrasonic inspection system)
Remove visual inspection by Boroscopy
Air born ultrasonic leak test
Helium leak test
A Fluorescent Dye Spray & UV Light Test
Wet fluorescent magnetic particle test
In-situ metallography for metallurgical condition and ageing assessment
Pressure Testing
Final Thoughts
As it is clear from the guide that heat exchanger is an important component. All along, the
best part is – It usually takes up minimal heat to transmitting the energy from one fluid to
the other.
Therefore, as a plant owner, learning and getting through these fundamentals become
pivotal by far.