Heat Transfer System Drain, Flush and Refill

Cleaning a heat transfer system | Drain, flush and refill | thermal oil

Cleaning a heat transfer system

The key to operating a cost effective and productive heat transfer system is regular cleaning. The heat transfer system will become fouled with debris and contaminants which occur naturally over the life of a thermal fluid.

Why should I drain, flush and refill a thermal fluid system?

All thermal fluids degrade over time because they are operating at a high temperature for long periods of time. As the fluid degrades it produces by-products that can contaminate the system.

Circulating debris can have negative consequences on the entire system if not managed properly. High levels of debris in a thermal fluid can erode pipework and accelerate the wear of components in the system such as pump seals. Larger particles can also settle, forming a sediment layer that increases thermal resistance, reducing the efficiency of the fluid and potentially forming hot spots.

Leaving debris in the system can cause erosion of its components, such as seals and pipes, leading to leaks. As soon as there is a leak, the facility is in breach of Dangerous Substances & Explosive Atmospheres Regulations (DSEAR) and the Explosive Atmosphere Directive (ATEX). This legislation sets the minimum requirements for protection against risk from fire, explosion and similar events that occur when working with dangerous substances in the workplace.

How do I know if the fluid needs replacing?

If the heat transfer system and internal fluid cannot maintain the required operating temperature of the process, the fluid may have degraded and could need replacing. Engineers might notice this if they are frequently turning up the temperature, but the flow rates have reduced.

You should always take a representative sample of the fluid to find out the current condition. Thermal fluid sample data may show high total acid number (TAN) / acidity (oxidation) and carbon residue data. The test results may also indicate likely levels of internal system fouling along with viscosity and particulate quantity results. If any suspended material in a heat transfer fluid reaches over five per cent of the total system volume, the fluid is no longer suitable for use.

Should I clean a new heat transfer system?

All systems need to be flushed and cleaned before fresh heat transfer oil is introduced.

This is extremely important when installing a new system because any welding slag, ferrous material or contaminants may not be removed during the manufacturing process. If these contaminants remain in the system, they can catalyse the oxidation of the thermal fluid and accelerate the degradation of the fluid.

Can I just drain the system?

Draining the system will remove the degraded fluid. However, there is no guarantee that all contaminants will be removed. Typically, up to 25 per cent of a systems’ fluid volume can remain after draining down due to the physical attributes of some parts of the system such as horizontal heater coils and dead legs in pipes.

Which cleaning fluid should I use?

Globaltherm® C1 is specially formulated to remove any harsh by-products of thermal fluids. This cleaning and flushing fluid is compatible with all organic heat transfer fluids and most synthetic based fluids.

Globaltherm® C1 is recommended for cleaning and flushing heat transfer systems that use heat transfer fluids in a temperature range from -90°C up to a maximum bulk temperature of 600°C. Unlike other products that traditionally only flush or clean the system, increasing downtime, this system cleaner can flush and clean in one step.

Where can I find help to clean my heat transfer system?

Our heat transfer system drain, flush and refill service can help you return your heat transfer system to maximum efficiency. Our engineers will help to thoroughly drain the system, safely remove the condemned fluid and flush out any carbon deposits.

We can also help with waste removal and disposal of condemned fluid in accordance with legislation and help you implement a preventative maintenance programme to extend the lifespan of your new fluid.

What does the drain, flush and refill service include?

Global Heat Transfer provides thorough flush, cleaning and thermal fluid replacement to ensure your system is completely purged and thermal fluids are refreshed to make sure your plant runs at maximum efficiency for longer.

The heat transfer system clean and flush service includes:

  • System drainage to safely remove existing fluid
  • System flush to remove contaminants
  • System fill using premium branded heat transfer fluids
  • System de-aeration to remove air and moisture
  • Waste removal and disposal of condemned thermal oil in accordance with government legislation
  • Post-works sample analysis to assess thermal fluid and performance

Where can I get more help with HTF maintenance?

The drain, flush and refill service can help to quickly get a new heat transfer system up to maximum efficiency when it is installed or return to it after a contaminated fluid is replaced.

Implementing a preventative maintenance programme is the best way to extend the lifespan of the virgin heat transfer fluid that is introduced to the system.

At Global Heat Transfer we provide a condition based thermal fluid lifecycle maintenance programme, Thermocare. Our expert engineers will work with you to improve accuracy when monitoring fluid condition, provide technical interventions when necessary, organise maintenance schedules and train staff.

The programme includes regular thermal fluid sampling and analysis to give you an accurate representation of fluid condition. This allows you to more accurately anticipate changes to fluid condition and system efficiency and plan maintenance accordingly. Frequent condition monitoring and applying appropriate intervention measures when necessary helps to extend the life of your fluid, while increasing system availability, reducing maintenance and energy costs and improving output.

Need more advice on cleaning a heat transfer system?

Global Heat Transfer offers a range of services and engineering support to help you improve heat transfer efficiency.

To speak to one of our experts call us on +44 (0)1785 760 555 or visit our contact page.

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