09/02/2019 | Boiler Water Treatment | 10 MINUTE READ

The Effects of High Conductivity in Boiler Water Treatment

municipal wastewater treatment

When you hear the term boiler water, this refers to any water that’s situated in a boiler or the pumps and piping surrounding the boiler for the main purpose of being evaporated into steam. Boiler water is used in many different industries for such applications as heating, sterilization, and humidification. These industries include metalworking, electrical, manufacturing, and agricultural industries.

A common problem that’s found in boiler water is the presence of high conductivity, which refers to the ability of the water to conduct an electrical current. Controlling the conductivity of water is an essential component of making sure that a boiler functions properly.

A key issue with high conductivity in boiler water is that operational issues such as scaling can occur, which is a buildup of solid material in the boiler. When this occurs, the boiler becomes less efficient and increases the fuel consumption of the unit. High conductivity levels also heighten the risk that the boiler water becomes contaminated, which can be very dangerous. If ever the conductivity in your boiler water reaches a higher level than it’s supposed to, you might want to look into obtaining boiler water treatment to effectively reduce conductivity levels and keep your boiler operational.

Measuring Conductivity of Boiler Water

If your business process includes a system heated by a boiler, it’s very important that you take the necessary steps to measure the conductivity of the boiler water that’s contained inside of the unit. Because of how important it is that the conductivity of the water is properly managed, you can’t afford to not measure the water. If you want to effectively measure the conductivity of the boiler water now and in the future, you need to understand how this measurement works and what you need to look for while measuring the water.

clean water drop

There are actually several different methods that can be used to measure the conductivity of boiler water. For instance, you should check the level of total dissolved solids to determine how conductive the water currently is. The TDS of your boiler water can either be measured by taking a sample of the water and measuring it externally from the boiler or by placing a sensor inside that’s designed to detect TDS levels. Keep in mind that a high TDS level indicates high conductivity in the water.

Products that Measure Conductivity

While you can use many different instruments to measure the conductivity of boiler water, among the most effective instruments is a toroidal conductivity sensor, which comes with digital communication for better ease-of-use. A high quality toroidal conductivity sensor will monitor total dissolved solids and conductivity.

While some contact conductivity sensors are prone to being affected by a wide range of issues that can cause them to malfunction in a relatively short period of time, the TCS3020 is resistant to corrosion, fouling, and coating, which is an essential feature if you want your conductivity sensor to have a long service life. Some of the features that are available with this instrument include a wide measurements range of up to 2,000mS, high resistance, and modern inductive measurement technology.

Once you’ve collected a sample of water from your boiler or have looked at the readings of the instrument you’re using, the main unit of measurement for conductivity is typically Siemens. When you receive the readings from a toroidal conductivity sensor, the results will be displayed as microSiemens per centimeter or uS/cm. Some conductivity sensors will also measure in milliSiemens per centimeter, which is a unit of measurement wherein one mS/cm is equal to 1,000 uS/cm. The TCS3020 is specifically ideal for such applications as chemical process and cooling towers. Higher numbers on the scale indicate that you might want to obtain boiler water treatment due to high conductivity.

measurement liquid beaker

The Effect of High Conductivity

The effects of high conductivity can be very damaging if you don’t stem them early on. It’s typically impossible to obtain completely pure water in a boiler. No matter the quality of your equipment, impurities will invariably seep into the water and begin to increase the water conductivity.

The impurities that get into your boiler water may be referred to as suspended matters, dissolved gases, or dissolved solids. The four major issues caused by the buildup of impurities include scaling, an oxygen attack, an acid attack, and boiler water carryover, all of which are problematic.

The Issue of Scaling

Scaling is likely the most common problem that’s caused by the high conductivity of boiler water. Scaling refers to the buildup of solid materials because of the reaction from the tube metal and the other impurities in the water. This buildup will lessen heat transfer in the boiler unit, which will invariably worsen boiler efficiency and cause an exceedingly high amount of fuel to be used in order to power the boiler.

water pipe corroding

If the issue lingers and isn’t tended to quickly, the presence of scale could cause the tubes to overheat and eventually fail. The thickness of the solid materials dictate how much fuel you’ll be wasting. It’s estimated that fuel consumption increases by 2-5 percent with the presence of scale, which will eventually cause you to lose a significant sum of money.

Oxygen’s Effects on Your Boiler System

As for an oxygen attack, this problem can cause your boiler system to corrode, which means that effectively managing the conductivity of your boiler water should result in a longer-lasting boiler. When oxygen dissolves in the feed water, it becomes heated and will react with the internal surface of the boiler, which causes corrosive elements to develop. These elements include red iron oxide and hematite. The presence of oxygen corrosion in a boiler system can eventually cause tube failure. Additional components of the boiler system can also be damaged, which include the condensate piping, boiler headers, and drums.

Acid Corrosion

An acid attack is another aspect of corrosion via high conductivity that occurs when the pH levels of feed water are lower than 8.5. Standard pH sensors will be able to help you identify the levels of pH in your boiler water. The carbonate alkalinity that’s found in the water is directly converted into CO2 by the pressure and heat from the boiler.

When the steam from the boiler condenses, carbonic acid is formed, which lessens the pH of the condensate that goes back into the boiler. As for boiler water carryover, this occurs when the steam from the boiler has become contaminated from boiler water solids. The presence of high boiler water solids creates foaming, which reduces the efficacy of the boiler.

mineral water bottle

High levels of salts, heavy metals, and other substances in water can be somewhat toxic to a person’s health if consumed in high amounts. The dangers to a person’s health extend from skin irritations to gastrointestinal issues. When you’re looking to measure the conductivity of your boiler water, it’s important that you keep the conductivity of the water at a certain level. If you want to prevent corrosion in your boiler, the water should have a conductivity reading that’s below 3,000 PPM, which equates to 6,000 µS/cm.

Treatment to Reduce Water Conductivity

If you find that the conductivity of your water is too high, you’ll want to obtain boiler water treatment to effectively reduce conductivity. With such Sensorex Products as the TX3100 and the SensoPro, you’ll be able to monitor the pH and TDS levels of your boiler water consistently, which will allow you to identify the exact moment when the conductivity in the water becomes too high.

At this point, you’ll need to use some type of boiler water treatment, of which there are many to choose from. If you decide to use external treatment methods, the water will be removed from the boiler before being purified. There are a wide variety of techniques that can be used for external boiler water treatment, which include softening, deaeration, membrane contractors, and evaporation. Each option ensures that the feed water you obtain is tailor-made for your boiler.

female drinking water

Internal Boiler Water Treatments

The internal treatment of boiler water involves a variety of solutions that can be placed directly into the boiler system in an attempt to prevent higher conductivity or to lower conductivity that has already reached a high measurement. As with external treatments, there are many methods and techniques that can be used via internal treatments.

No matter which internal treatment you use, the main goals of each treatment include preventing impurities in the water from becoming scale, conditioning suspended matter in the boiler to the point that it doesn’t adhere to surface metal, preventing foam from developing, and eliminating the oxygen in the water.

The main internal treatment solutions that you might want to consider include softening chemicals, anti-scaling agents, oxygen scavengers, sequestering agents, and anti-foaming agents, all of which can help with the reduction of conductivity. It’s important for you to control the conductivity of your boiler water in order to prevent damaging to the boiler.

The buildup of scale, acid, and corrosion in the water can significantly lessen the lifespan of your boiler system. Even before these issues cause your boiler to become damaging, the efficiency of the unit will worsen, which will waste water and energy. By controlling the water conductivity, you’ll be able to save money and keep your boiler system functioning properly for many years.

Preparing and Maintaining Safe Levels of Conductivity

Water control sensors and conductivity sensors will help you maintain safe levels of conductivity in your boiler system in a variety of different ways. As mentioned previously, the SensoPro system displays TDS levels, salinity, and current conductivity. There are also very little maintenance requirements for these sensors, which should save you time and money. When you want to determine if the pH levels of your boiler water have dipped to a dangerously low level, the TX2000 will provide you with very precise measurements.

beakers chemical

By using the appropriate sensors and products, you’ll be able to continuously monitor the conductivity of your boiler water without any effort on your part. The benefits of doing so are numerous. Controlling the pH levels and conductivity of the feed water in your boiler will help you reduce the possibility of boiler water carryover into your steam system, eliminate the possibility of overfeeding chemicals, reduce the amount of time that you spend testing the system, and eliminate the need to regularly remove highly conductive water, which causes you to waste chemicals, water, and energy. By selecting the appropriate sensors now, you can control conductivity levels before they become too high, which will help your business save money and energy that can be better used elsewhere.


Measuring and maintaining the conductivity levels of boiler water is one of the most important aspects within metalworking, electrical, manufacturing, and agricultural industries. If you are interested in purchasing one of many products to help measure the conductivity levels of boiler water, check out our products page to search for the best product for your business. If you have any questions with any water treatment applications, contact our Sensorex team today!

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Posted by Dominic O'Donnell on September 2, 2019

Sensorex is a global leader in the design and manufacture of quality sensors for water quality and process applications. The company offers more than 2000 sensor packages for pH, ORP, conductivity, dissolved oxygen, free chlorine, chlorine dioxide, UV transmittance and other specialty measurements, as well as a full line of sensor accessories and transmitters. Its expert technical support engineers solve analytical sensor challenges with custom designs and off the shelf products.

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