Leakage Detection Systems: Considerations for Corrosive and Non-Corrosive MaterialsFebruary 25, 2021 by Muhammad Asim Niazi
Learn about the essential aspects of liquid leakage detection systems and considerations for detection systems used with corrosive and non-corrosive materials.
A liquid leakage detection system detects unwanted liquid leakage and flow. A liquid leakage can pose a serious threat for humans and infrastructures and wastes precious liquid – often an integral part of a production process.
In many industries, liquid leakages are inevitable and do not mean the systems are shoddy. Liquids have a natural tendency to flow in a molecular form, making leakages routine. Piping and storage vessels intended for liquid applications can leak from broken joints, cracked parts, or vibration. For these reasons, liquid leakage detection systems are important techniques to safeguard and prevent leaks from becoming worse.
Figure 1. Liquid leakage detection systems safeguard against inevitable leaks becoming dangerous problems.
Considerations for Liquid Detection Systems
There are essential aspects to consider when designing liquid detection systems including:
- The type of liquid
- Area of application
- Desired temperature
- Cable length
- The system’s electrical characteristics
Let’s look at each of these considerations in more detail.
Type of Liquid
Different liquids have certain characteristics that affect the detector’s performance. Conductivity and viscosity are the main characteristics of liquid that direct the detection system material selection. Inattention to these characteristics makes the output erratic.
Area of Application
This consideration pertains to where the detector system is applied. Is it for piping systems or storage vessels? For vessels underground or above ground? All this information is necessary when designing or selecting a leakage detection system. Manufacturers offer liquid leakage detection systems in different mounting types to cater to different requirements.
Figure 2. K7L sensors are used in the specific application of detection of cleaning fluid level for plating devices. Image courtesy of Omron.
Higher temperature values are common in most process and manufacturing industries, including distilled water and oil and gas. For these extreme conditions, the temperature-bearing property of the detector is important for the detector to withstand the extreme highs and lows of the liquid’s temperature.
Liquid leakage detectors are often installed far away from the main electrical panel. For example, in the case of a lengthy piping network throughout a facility.
Neglecting this distance causes attenuation of signal strength and erratic readings. Manufacturers create special models, enough to withstand signal attenuation and loss.
Electrical characteristics include electrical parameters used to power-up the system, how the controller uses output for further data acquisition. Commonly it includes:
- Power Supply
- Input Resistance
- Wire break Function: Detects a wire break and is particularly helpful in lengthy applications.
- Output: There are two outputs – normally open and normally closed. This depends on the type of controller used.
A liquid’s properties plays a crucial role in the performance of the leak detection system and its up to the designer to establish design preferences. Among the properties of the liquid is corrosiveness.
When corrosive liquids such as acidic liquids and seawater come in contact with the detector system, it degrades the detector’s components. The degradation decreases the performance and life of the detector.
To provide optimum perforation and prevent the leakage detection system from degradation, special care is required.
Corrosive Resistant Material
Special materials tend to withstand corrosive effects and provide an excellent barrier to corrosion. These corrosive-resistant materials are used in the manufacturing of detection system components that come in direct contact with the liquid.
During the selection of leakage detection systems, look-out for these corrosive-resistant materials — this information is readily available on the technical datasheet.
When the detector comes in contact with the corrosive liquid, traces are left on the leakage detector. Cleaning the detector’s external and visible parts keeps the detector safe and protects it from the effects of corrosion.
Regular calibration is an effective way to prevent leak detection systems from the consequences of corrosive materials. When corrosion starts to effect the performance of the leak detection system, calibration helps to identify the degree and amount of error a detector has in it.
Consistent calibration helps to identify erratic readings befor more serious errors happen. Every leak detector’s reading follows the reference values as set by the manufacturer. A deviation from the reference values represents a malfunction in the detector. The error can be removed by in-house technical personnel or is sent to outside specialists depending on the fault.
For the detector’s optimum calibration, the manufacturer’s recommendations are a useful source of information. The manufacturer provides a detailed guideline for calibration procedures and frequency recommendations.
A liquid detection system for non-corrosive liquids does not require additional safety procedures. The material for handling normal liquids can be used such as Stainless Steel 316 or Stainless Steel 316L. Calibration is necessary to detect drifts in the detector output.
Liquid leakage detection systems have proved themselves an excellent choice to detect and prevent liquid leaks. Technology advancements have enabled these systems to work in every industry and environment. However, careful selection of leak detectors is crucial. Knowing the basic requirements along with the vendor-supplied data speeds up the selection process.