Anti-corrosive Pressure Transmitter: The Ultimate Guide for Corrosive Working Conditions

In industrial production scenarios such as chemical engineering, pharmaceutical manufacturing, sewage treatment, and marine engineering, corrosive media (acids, alkalis, salts, organic solvents, etc.) are common. These media not only erode equipment but also cause inaccurate pressure measurement, equipment failure, and even safety accidents. As a core component for pressure monitoring in corrosive environments, the anti-corrosive pressure transmitter directly determines the stability of the production line and the accuracy of data. How to choose a suitable anti-corrosive pressure transmitter? What are the key points for daily maintenance? This guide will answer all your questions.

1. What is an Anti-corrosive Pressure Transmitter? What makes it unique?

The working principle of corrosion-resistant pressure transmitters is basically the same as that of ordinary pressure transmitters: it converts the pressure signal of the measured medium into a standard electrical signal (4-20mA, 0-10V, etc.) through a sensor, and then transmits this signal to a display instrument, controller, or DCS system for data monitoring and control. The core difference lies in its corrosion-resistant design: it generally uses a ceramic core, and the corrosion resistance, chemical stability, and structural adaptability of ceramic materials perfectly meet the needs of harsh corrosive working conditions.

2. Key Selection Criteria for Anti-corrosive Pressure Transmitter

2.1 Different corrosive media have different requirements for anti-corrosive materials. For example: for general acid and alkali media, 316L stainless steel can meet the requirements; for strong corrosive media such as hydrofluoric acid and chlorine gas, Hastelloy or PTFE-lined materials are required; for high-temperature and high-pressure corrosive media, it is necessary to choose materials with high-temperature resistance and high-pressure resistance at the same time. Before selection, you must clearly understand the composition, concentration, temperature and pressure of the measured medium.

2.2 Select the Appropriate Measurement Range and Accuracy

According to the actual pressure range of the working condition, select the transmitter with a suitable measurement range (it is recommended that the actual measured pressure is within 30%-70% of the full scale to ensure measurement accuracy). At the same time, according to the production process requirements, select the appropriate accuracy level (common 0.1%FS, 0.2%FS, 0.5%FS). For scenarios that require precise control (such as pharmaceutical dosing), a higher accuracy level should be selected.

2.3 Pay Attention to the Anti-corrosive Structure Design

The structural design directly affects the anti-corrosive effect and service life. It is recommended to choose products with full-welded structure and isolated diaphragm design: the full-welded structure can avoid leakage of corrosive media; the isolated diaphragm can effectively isolate the sensor core from the corrosive medium. In addition, for scenarios with high humidity or dust, products with IP68 protection level should be selected to prevent moisture and dust from entering the equipment.

2.4 Consider the Working Environment Temperature

The structural design directly affects the anti-corrosive effect and service life. It is recommended to choose products with full-welded structure and isolated diaphragm design: the full-welded structure can avoid leakage of corrosive media; the isolated diaphragm can effectively isolate the sensor core from the corrosive medium. In addition, for scenarios with high humidity or dust, products with IP68 protection level should be selected to prevent moisture and dust from entering the equipment.

2.5 Confirm the Output Signal and Installation Method

According to the on-site control system, select the appropriate output signal (4-20mA current signal is the most common, with strong anti-interference ability; 0-10V voltage signal is suitable for short-distance transmission). At the same time, according to the installation location (such as tank top, pipeline, outdoor), select the appropriate installation method (flange installation, thread installation, bracket installation) to ensure convenient installation and maintenance.

3. Typical Application Scenarios of Anti-corrosive Pressure Transmitter

Due to its excellent anti-corrosive performance, the anti-corrosive pressure transmitter is widely used in various industrial fields with corrosive working conditions. Here are several typical application scenarios:

3.1 Chemical Industry

In the production process of chemicals (such as sulfuric acid, hydrochloric acid, nitric acid), corrosive media are involved in multiple links such as reaction kettles, storage tanks, and pipelines. The anti-corrosive pressure transmitter is used to monitor the pressure of the medium in real time, ensuring the safety and stability of the production process. For example, in the sulfuric acid production line, PTFE-lined anti-corrosive pressure transmitters are used to avoid corrosion of the equipment by concentrated sulfuric acid.

3.2 Sewage Treatment Industry

Sewage (especially industrial sewage) contains a lot of corrosive substances such as organic acids, heavy metal ions, and salts. The anti-corrosive pressure transmitter is used to monitor the pressure of sewage in the treatment process (such as aeration tanks, sedimentation tanks, and discharge pipelines), ensuring the normal operation of the sewage treatment equipment. In coastal areas, it is also necessary to consider the corrosion of seawater, so 316L stainless steel or Hastelloy materials should be selected.

3.3 Pharmaceutical Industry

In the pharmaceutical production process, corrosive media such as acids, alkalis, and organic solvents are often used for extraction, purification, and disinfection. The anti-corrosive pressure transmitter not only needs to have good anti-corrosive performance but also needs to meet the GMP certification requirements (such as no dead ends, easy cleaning). It is usually used in links such as pharmaceutical reaction kettles and solvent storage tanks to ensure the quality and safety of pharmaceuticals.

3.4 Marine Engineering

Marine environments (seawater, salt spray) have strong corrosiveness. The anti-corrosive pressure transmitter is used in marine equipment such as ships, offshore oil platforms, and seawater desalination equipment to monitor the pressure of seawater, fuel oil, and other media. It is required to have not only anti-corrosive performance but also anti-shock and anti-vibration performance to adapt to the harsh marine environment.

4. Daily Maintenance Tips for Anti-corrosive Pressure Transmitter

Proper daily maintenance can extend the service life of the anti-corrosive pressure transmitter and ensure measurement accuracy. Here are 4 key maintenance tips:

•Regular Inspection of Anti-corrosive Coating/ Lining: For transmitters with PTFE lining or anti-corrosive coating, regularly check whether the coating/lining is intact (whether there are cracks, falling off, etc.). If damage is found, it should be repaired or replaced in time to avoid corrosion of the base material.

•Clean the Isolation Diaphragm Regularly: The isolation diaphragm is in direct contact with the corrosive medium. After long-term use, dirt or crystals may adhere to the surface, affecting pressure transmission. It should be cleaned regularly with a non-corrosive cleaning agent (avoid scratching the diaphragm).

•Check the Tightness of Connections: Regularly check the tightness of the transmitter's wiring terminals, flange connections, and thread connections to avoid leakage of corrosive media or entry of moisture, which may cause equipment failure.

•Calibrate Measurement Accuracy Regularly: According to the production requirements (usually once every 6 months to 1 year), calibrate the measurement accuracy of the transmitter. If the accuracy exceeds the allowable range, adjust or repair it in time.

5. How to Choose a Reliable Anti-corrosive Pressure Transmitter Supplier?

Choosing a reliable supplier is as important as choosing a suitable product. When selecting a supplier, you can pay attention to the following points: 1) Whether there is professional technical support (such as providing customized solutions according to working conditions); 2) Whether the product has complete certifications (such as ISO9001 quality system certification, IP68 protection level certification); 3) Whether there is a perfect after-sales service (such as 24-hour technical consultation, on-site installation and debugging, maintenance services);

4) Whether there are successful application cases in the same industry (you can ask for case sharing and user testimonials).