In chemical plants, measuring liquid levels accurately and reliably is critical for maintaining safe and efficient operations. One of the most widely used remote telemetry signal liquid level sensors is the static pressure liquid level transmitter. This method calculates the liquid level by measuring the static pressure of the liquid column in the vessel. In this article, we will discuss the key selection points and usage conditions of the XDB502 liquid level sensor in chemical equipment.
Features and Advantages
The XDB502 liquid level sensor has several features and advantages that make it suitable for a wide range of applications in chemical plants. These include:
Applicability in high-temperature, high-pressure, high-viscosity, and highly corrosive environments, making it suitable for a broad range of applications.
Large measuring range that varies according to the area, and no blind spots.
High reliability, stability, long life, and low maintenance costs.
High-precision measurement, with accuracy up to +0.075% full scale (f.s.) for imported static pressure liquid level transmitters and +0.25% f.s. for traditional domestic static pressure liquid level transmitters.
Intelligent self-diagnosis and remote setting functions.
Diverse signal output options, including different protocols for standard 4mA-20mA current signals, pulse signals, and fieldbus communication signals.
Selection Points
When selecting a static pressure liquid level transmitter, the following points should be considered:
If the equivalent range (differential pressure) is less than 5KPa and the density of the measured medium changes more than 5% of the design value, a differential pressure liquid level transmitter should not be used.
The liquid’s flammability, explosiveness, toxicity, corrosiveness, viscosity, presence of suspended particles, evaporation tendency, and tendency to condense at ambient temperatures should be considered when selecting a transmitter.
The transmitter can be designed with either single or double flanges. For double flange transmitters, the capillary length should be equal.
For liquids that are prone to crystallization, sedimentation, high viscosity, coking, or polymerization, a diaphragm type differential pressure liquid level transmitter with an insertion sealing method should be selected.
In environments where the gas phase can condense and the liquid phase can evaporate, and the container is under high-temperature and high-pressure conditions, a condenser, isolator, and balance container should be installed when using a regular differential pressure liquid level transmitter for liquid level measurement.
The actual differential pressure liquid level transmitter typically requires range conversion. Therefore, the transmitter should have a range offset function, and the offset amount should be at least 100% of the upper limit of the range. When selecting a transmitter, the offset should be considered, especially when measuring high-density media. Therefore, the transmitter’s range should be chosen based on the offset situation.
Usage Conditions
The XDB502 liquid level sensor has several usage conditions that must be considered:
Process temperature: This type of transmitter operates by conveying pressure through a filling liquid sealed within the device. Common filling liquids include 200 silicone, 704 silicone, chlorinated hydrocarbons, mixtures of glycerol and water, among others. Each filling liquid has an appropriate temperature range, and the filling type should be selected based on the chemical properties of the measured medium and the process temperature. Therefore, when the process temperature exceeds 200℃, the use of a diaphragm-sealed transmitter should be carefully considered. If necessary, an extended sealing system or thermal optimization device should be selected, and the transmitter manufacturer should confirm the details.
Ambient temperature: The filling liquid should be filled at an appropriate ambient temperature. The capillary must be kept consistent with the filling liquid’s temperature. As the epoxyethane in flammable EOEG devices is prone to polymerization, a diaphragm-sealed differential pressure liquid level transmitter should be used to measure the epoxyethane medium’s level. As carbonate solutions are prone to crystallization, a diaphragm-sealed differential pressure liquid level transmitter with an insertion sealing system should be used, with the insertion point flush with the equipment’s inner wall. The insertion’s outer diameter and length are determined based on the equipment’s specifications. For equipment with a drum operating temperature of 250℃ or higher, a regular pressure pipeline should be used.
Conclusion
In conclusion, the XDB502 liquid level sensor is a reliable and accurate option for measuring liquid levels in chemical plants. It has several advantages, including a wide range, high precision, diverse signal output options, and intelligent self-diagnosis. When selecting a transmitter, the liquid’s properties, such as flammability, explosiveness, toxicity, corrosiveness, and viscosity, must be considered. Additionally, usage conditions such as process temperature and ambient temperature should be taken into account to ensure accurate and reliable measurements.
Post time: May-08-2023