Your Heat Exchanger
9/25/20, by Toni Wall
Your heat exchanger: you know...that piece of equipment in your plant that you may not think about often, since most can last 10-20 years running just fine, out of sight and out of mind. In case you are new to the industry let's do a quick tutorial. A heat exchanger is a system that transfers heat by using two or more fluids. They can be used in both cooling and heating systems. The most common type of heat exchanger found in most Power Plants, Chemical Processing, Food & Beverage, Hospitals, Colleges, or Pharmaceutical plants are called a shell and tube system.
How it works: A fluid (media) flows through the tubes, while another fluid, often water, circulates throughout the shell and around the tubes to cool or heat the fluid flowing through the tubes.
How it fails: Failure can be caused by several culprits, however most often (not always) it's a tube bundle leak, where the tube media ends up mixed in with the shell side media causing the unit to no longer function properly. Unfortunately, that heat exchanger system that you have walked by for years without an issue, has now become a major problem.
Review Your Options:
How to avoid costly downtime:
Have a spare on hand. The plant will have to prepare for the worst situation in the event of failure. With this said the next topic becomes critical in reducing downtime.
Do not throw away your TUBE BUNDLE
This is very important and is potentially money in the bank for your organization. Choosing to re-tube the bundle will not only help with reducing or eliminating downtime, but it is also much less of an investment. You can re-tube an existing bundle for a fraction of the cost of a new one. Most often, a reputable service company can salvage the old bundle for you. We estimate that 90% of the time the tube bundle is the cause of the failure. Even if you decide that it is time for a new piece of equipment, having an available spare unit can save you considerable money and downtime should a failure occur.
Tube bundle delivery options:
The delivery of a new bundle can be 6 to 18 weeks from the OEM. Re-tubing a bundle can be as little as a few days to several weeks. Sometimes the availability of the tube material can contribute to a longer delivery but International Valve & Instrument will quote you all of the details, expedite, and get you back into operation as quickly as humanly possible.
Will I just need a tube bundle?
Yes, most of the time, as the two largest heat exchanger components, the shell and head, might require some attention, however most likely they will not require replacing. We can also provide a diagnostic of the shell and head and all components for any necessary corrective action.
Oh, NO I do not have time for this!
Regardless of how talented your maintenance staff is, you should most likely find a reputable repair/service company to come and perform a diagnostic test. Understanding where to go from the start can save you time and money and International Valve and Instrument understands how to secure the correct information from your heat exchanger nameplate so they ensure they process this information through the appropriate agency who can then provide the critically important information on the correct tube configuration, tube material and/or the proper tube gauge. Having all of this information upfront is essential for us to be able to make a solid informed decision on how best to repair your unit.
Where do we go from here?
Is your heat exchanger fit for life? No, but “don't panic”. International Valve & Instrument can provide you several options including re-tube or replicate the tube bundle.
If at all possible, having a spare tube bundle is always your best option, especially if the original O.E.M. is no longer in business. Some units can also be repaired on-site and be back running in no time by testing tubes, replacing and/or plugging them and thus getting the plant up and running again as quickly as possible. Your equipment is by no means worthless and as a reputable repair company we can let you know that even if the unit should be replaced, does it makes sense to repair the tube bundle and keep it as a critical spare.