In industries such as chemical engineering, pharmaceuticals, and petrochemicals that have extremely high requirements for safety and environmental protection, the sealing performance of chemical pumps is directly related to production safety, medium purity, and equipment service life. Once leakage occurs, it will not only cause the loss of expensive materials but also may lead to safety accidents or environmental pollution. So, how to achieve high sealing performance in chemical pumps? This article will deeply analyze the core technologies for achieving high sealing performance.
The media transported by chemical pumps often have characteristics such as corrosiveness, abrasiveness, high temperature, high pressure, toxicity, or flammability and explosiveness. These harsh working conditions place extremely high demands on the sealing system:
Therefore, a reliable sealing system is the cornerstone for the efficient and safe operation of chemical pumps. This requires the collaborative guarantee of static sealing and dynamic sealing, combined with scientific initial management, to maximize sealing reliability.
To achieve high sealing performance in chemical pumps, precise control is required from three core dimensions: sealing structure design, materials science, and manufacturing processes. At the same time, the applicable scenarios of different sealing forms should be clarified to avoid blind selection.
Static Sealing: O-rings as the mainstream choiceFor static sealing, there are usually only two forms: gaskets and sealing rings, among which O-rings are the most widely used. The materials for static sealing of chemical pumps generally adopt fluororubber, and polytetrafluoroethylene (PTFE) materials are used only in special cases. This choice is mainly based on their excellent corrosion resistance and sealing performance.
Dynamic Sealing: Mechanical seals as the preferred optionChemical pumps rarely use packing seals, and mechanical seals are the main choice. Mechanical seals can be divided into single-end and double-end, balanced and unbalanced types. Balanced mechanical seals are suitable for sealing high-pressure media (usually referring to pressure greater than 1.0MPa), while double-end mechanical seals are mainly used for media with high temperature, easy crystallization, viscosity, particles, and toxic volatilization. For double-end mechanical seals, an isolation fluid should be injected into the seal chamber, and its pressure is generally 0.07~0.1MPa higher than the medium pressure.
The material configuration of the dynamic and static rings of mechanical seals is relatively critical. It is not that the combination of cemented carbide and cemented carbide is the best. On the one hand, the price is high; on the other hand, the lack of hardness difference between the two is unreasonable. Therefore, it is best to treat them differently according to the characteristics of the medium. For example, for strong acid/strong alkali media, the SiC/SiC combination is recommended; for slurries containing particles, materials with stronger wear resistance need to be considered.
No matter how good the structural design and materials are, insufficient manufacturing and assembly precision will lead to seal failure. Therefore, it is necessary to strictly control two core links: first, high-precision processing. The flatness, roughness, and perpendicularity of the seal end face must reach micron-level precision to avoid leakage caused by end face defects; second, clean assembly. Any tiny impurity particles may scratch the seal end face. Therefore, assembly must be carried out in a clean environment, and professional installation guidelines must be strictly followed to ensure that the spring compression, shaft coaxiality, seal chamber cleanliness, etc., meet the standards.
To ensure that chemical pumps maintain high sealing performance for a long time, attention must be paid to the initial operation management of the equipment. This includes:
1.Commissioning and adjustment during the initial operation of the equipment, accurately adjusting various parameters of the sealing system to achieve the sealing function expected by the original design.
2.Conduct technical training on the use and maintenance for operators, focusing on explaining the key points of daily inspection of the sealing system, the specifications for replacing isolation fluid, the judgment methods for abnormal leakage, and other core contents.
3.Strengthen the monitoring of the initial operation status, carefully observe and record data such as leakage, temperature changes, and abnormal noise of the sealing system, and timely analyze and handle potential problems.
4.Formulate a special information management process for the sealing system, complete the original records of initial failures, fill in the equipment initial operation appraisal form and seal commissioning records, etc., to provide data support for subsequent maintenance.
5.The user department must provide all original data completely, including the actual operating hours of the pump, the medium parameters in contact with the sealing system, the damage and failure records of parts, and early failure records.
6.Conduct in-depth research on typical failures of the sealing system and component failures, analyze the root causes, and propose improvement measures, such as optimizing the isolation fluid pressure and adjusting the seal material pairing.
7.If defects in the original design or manufacturing of the sealing system are found, put forward reasonable improvement suggestions in a timely manner to improve sealing reliability through corrective maintenance.
8.Conduct a technical and economic analysis of the initial operating costs of the sealing system (such as isolation fluid consumption, spare parts replacement costs) and sealing effects, form an evaluation report, and provide a basis for subsequent optimization.
As a world-leading manufacturer of industrial fluid equipment, Athena Group deeply understands the stringent requirements of the chemical industry for pump sealing performance. Its Teffiko brand chemical pumps provide a full-process high-sealing solution from selection and manufacturing to initial operation management guidance.
Athena Group and its Teffiko brand have always placed the reliability and safety of products at the forefront. We not only provide high-quality pump products but also strive to be a trustworthy fluid solution partner for customers. From sealing system design and product manufacturing to later maintenance guidance, we will fully protect your safe production.
If you are looking for centrifugal pumps with high sealing performance for your chemical equipment or need professional suggestions on sealing system optimization, please feel free to contact Teffiko. Our technical experts will provide you with the most accurate consultation and the most optimized solutions.
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