A grounding ring, a crucial component of an electromagnetic flowmeter, conducts the electromotive force generated by the fluid flowing through the pipe to the ground, ensuring that the zero point of the measured potential matches the medium's potential, thus preventing errors.
Electromagnetic flowmeters operate based on Faraday's law of electromagnetic induction. Using a grounding ring ensures stable and accurate operation of the flowmeter under harsh or special conditions.
When the flowmeter is installed on plastic pipes, metal pipes with insulating linings, or pipes with cathodic protection, the measured medium cannot be naturally grounded due to the pipe's insulation. In such cases, a grounding ring must be used to establish a grounding loop.
Application Scenarios
Chemical Industry: Grounding rings ensure electromagnetic flowmeters maintain high measurement accuracy even in highly corrosive environments, especially when using PTFE-lined sensors. The grounding ring not only provides grounding but also protects the lining structure.
Water Treatment Industry: When these flowmeters are installed on cathodic-protected water pipelines, the inner and outer walls of the pipeline are insulated to prevent electrolytic corrosion, and the measured medium has no ground potential. In this case, grounding rings must be installed on both sides of the sensor and connected to a dedicated grounding electrode via a grounding wire.
Oil and Metallurgical Industry: Pipelines often use special coatings or linings to prevent corrosion, and these insulating layers can block the natural grounding path. Grounding rings can establish a reliable grounding connection in such situations. Compared to the traditional method of applying a conductive coating to the outside of the pipeline, grounding rings offer greater conductivity and do not age or fail over time.
How to Choose the Right Material
Choosing the appropriate grounding ring material and type is crucial for ensuring the long-term stable operation of electromagnetic flowmeters. The grounding ring material needs to be selected based on the chemical properties, temperature, pressure, and wear characteristics of the measured medium.
Common grounding ring materials include: 316L stainless steel, Hastelloy B, Hastelloy C, titanium, and tantalum.
|
Material |
Applicable environment |
|
316L |
Industrial water, domestic water, sewage, neutral solution, and weak acids such as carbonic acid, acetic acid, and other weak corrosive media. |
|
HC |
It is resistant to oxidizing acids, such as mixtures of nitric acid, chromic acid, and sulfuric acid. It also resists corrosion from oxidizing salts or other oxidizing environments. It exhibits good corrosion resistance to seawater, salt solutions, and chloride solutions. |
|
Ti |
Corrosion resistant to seawater, various chlorides and hypochlorites, and various hydroxides. |
|
Ta |
Resistant to almost all chemical media except hydrofluoric acid. Due to the high price. It is only used for hydrochloric acid and concentrated sulfuric acid. |
We offer grounding rings for electromagnetic flowmeters; materials and specifications can be customized. Contact us today for a free quote.
Post time: Dec-05-2025