Measurement and Control Equipment

Condensate Contamination Monitoring System: Automatic Dumping by Conductivity

Discover condensate contamination monitoring systems that detect condensate polluted by failures such as heat exchanger leaks using conductivity, and dump it automatically.

ORFA Technical TeamUpdated: Oct 30, 20263 min read

Condensate contamination monitoring system with conductivity probe and dump valve

Returning as much clean condensate as possible to the boiler feed tank saves water, treatment chemicals and fuel. However, when a heating coil or heat exchanger plate leaks, the product being heated can enter the condensate line. A condensate contamination monitoring system continuously measures the electrical conductivity of the condensate, detects such contamination immediately and automatically diverts contaminated condensate before it reaches the boiler.

Why Is Contaminated Condensate Dangerous?

When contaminated condensate mixes with feed water it can cause foaming and carryover in the boiler, scale and deposits on heating surfaces, and corrosion. Heat transfer deteriorates, boiler efficiency falls and boiler life is shortened. Contamination in recovered condensate must therefore be detected and controlled without delay.

Working Principle

The system is installed in the condensate line upstream of the condensate tank inlet and works as follows:

A conductivity probe continuously measures the conductivity of the passing condensate.
The measured value is sent to the controller.
The controller compares it with a preset set point.
If conductivity exceeds the set point, the dump valve opens automatically and the contaminated condensate is sent to drain.
When conductivity drops below the set point, the dump valve closes and clean condensate flows to the condensate tank again.

Tip: The conductivity of water changes significantly with temperature (it rises as temperature rises). The probe must therefore measure temperature as well, and the controller must compensate the reading to a reference temperature; otherwise hot but clean condensate could be treated as contaminated.

Which Contaminants Can It Detect?

Contaminant	Detectability by conductivity
Hard water, cooling water or brine leaks	Well detected (dissolved salts raise conductivity)
Acids, caustics and cleaning (CIP) chemicals	Well detected
Salt-containing food products such as milk or juice	Usually detected
Non-ionic substances such as oil or sugar solutions	Poorly detected; consider turbidity or oil detection sensors for these risks

Installation Notes

Install the probe where the condensate line runs full and no air pockets form.
Place the dump valve far enough downstream that contaminated condensate can be diverted before it reaches the tank.
Set the set point for each site by measuring the normal conductivity of clean condensate.
Provide a suitable drain line for the hot dumped condensate and, if necessary, cooling.

Benefits

Boiler protection: Prevents contaminated condensate from entering the feed water and extends boiler life.
Efficiency: Helps keep heating surfaces clean and preserves heat transfer.
Resource savings: Allows clean condensate to be recovered safely, reducing water, chemical and energy losses.
Automatic control: Dumping takes place without operator intervention.
Early warning: Failures such as heat exchanger leaks are noticed early, preventing greater damage.

Applications

Food and beverage processing plants
Chemical plants
Textile mills
Power plants
Any industrial steam system with condensate recovery

Frequently Asked Questions

Where is the system installed?

In the condensate return line, upstream of the condensate tank inlet, so that contaminated condensate can be dumped before it reaches the tank and the boiler.

Why is temperature important for conductivity measurement?

Water conductivity varies with temperature. Without temperature compensation, condensate of the same quality shows different conductivity at different temperatures, leading to wrong dump decisions.

Will it detect an oil leak?

Oil does not conduct electricity, so it cannot be detected reliably by conductivity. Where non-ionic contamination such as oil or sugar is a risk, turbidity or oil detection sensors should also be considered.

Conclusion

A condensate contamination monitoring system continuously watches condensate quality, protects the boiler from contaminated feed water, allows clean condensate to be recovered safely and helps detect failures early. Correct probe location, temperature compensation and a site-specific set point determine its effectiveness. Explore other solutions for boiler water quality on our Boiler Surface and Bottom Blowdown Systems page and contact the ORFA technical team for support.

Online Store