Key Selection Points for Pump Mechanical Seals in Chemical Pumps: Avoiding Medium Corrosion and High-Temperature Leakage Issues
Views: 0 Author: Site Editor Publish Time: 2026-01-23 Origin: Site
Chemical pumps serve as core equipment for fluid transfer, and their operational stability is directly tied to production safety and continuity. Pump mechanical seals are critical sealing components for chemical pumps, playing a pivotal role in preventing medium leakage and ensuring efficient, pressure-resistant equipment operation. In chemical working conditions, media typically contain corrosive components such as strong acids and alkalis, often accompanied by high-temperature and high-pressure environments. Improper selection of pump mechanical seals can easily lead to seal face wear, failure, and leakage, triggering safety incidents and economic losses. Therefore, the scientific selection of pump mechanical seals based on working condition characteristics and medium properties to accurately avoid corrosion and high-temperature leakage risks is a core technical priority in the design and operation of chemical pump systems.
Matching medium characteristics is the primary technical prerequisite for selecting pump mechanical seals. For corrosive media, the rotating and stationary rings of pump mechanical seals should be made of corrosion-resistant hard materials like silicon carbide and silicon nitride, while the sealing rings should be paired with corrosion-resistant elastomers such as fluororubber and perfluoroelastomer. This prevents seal failure caused by medium erosion at the material level. Additionally, selection should be optimized based on medium viscosity and particle content: for high-viscosity media, seal face structures with low friction coefficients are preferred; for media containing solid particles, sealed structures with flushing circuits should be adopted to avoid abrasive failure from particles embedding in the seal faces.
Medium Type
Recommended Material for Rotating & Stationary Rings
Recommended Material for Sealing Rings
Application Scenarios
Strong acids/alkalis
Silicon carbide, silicon nitride
Perfluoroelastomer
Chemical reactors, acid-alkali transfer pumps
Media with solid particles
Tungsten carbide alloy, silicon carbide
Fluororubber
Pulp pumps, mineral slurry transfer pumps
High-temperature organic solvents
Metal-impregnated graphite, silicon carbide
Fluororubber
High-temperature solvent distillation tower transfer pumps
Ordinary water-based media
Alumina ceramics, graphite
Nitrile rubber
Normal-temperature circulating water transfer pumps
Matching working condition parameters is a core technical step to ensure the stable operation of pump mechanical seals. For high-temperature conditions (medium temperature > 150℃), metal bellows-type structures should be prioritized. Their springless design prevents high-temperature creep failure, and their seal face heat resistance outperforms conventional spring-type structures. For high-pressure conditions (seal chamber pressure > 1.6MPa), the rated pressure resistance of the seal components must be verified to ensure it is at least 1.2 times the actual working pressure, preventing seal face deformation and end-face specific pressure imbalance caused by high pressure. Furthermore, seal face width and material hardness should be optimized based on pump shaft speed; for speeds > 3000r/min, high-strength silicon carbide should be used for the seal faces to reduce wear rates from high-speed friction.
Seal Structure Type
Suitable Working Conditions
Core Technical Advantages
Leakage Rate Level
Single-face spring-type
Normal temperature, low pressure, weakly corrosive media
Compact structure, low maintenance cost
≤10⁻⊃3;mg/s
Double-face bellows-type
High temperature (>150℃), high pressure (>1.6MPa), highly corrosive media
Double-seal protection, resistance to high-temperature creep
≤10⁻⁶mg/s
Cartridge mechanical seal
Frequent disassembly scenarios, complex working conditions
High installation accuracy, no on-site debugging required
≤10⁻⁴mg/s
Seal structure and auxiliary system configuration directly impact the adaptability of pump mechanical seals. Single-face structures are suitable for non-toxic, weakly corrosive, low-pressure conditions, featuring compact designs and low maintenance costs. Double-face structures adopt barrier fluid circulation protection, making them ideal for toxic, highly corrosive, high-temperature, and high-pressure harsh conditions, with leakage rates controllable below 10⁻⁶mg/s. For auxiliary systems, cooling jackets (cooling medium temperature difference ≤20℃) are required for high-temperature conditions, while thermal insulation and flushing systems are necessary for easily crystallizable media. Continuous flushing prevents medium crystallization from clogging the seal chamber, extending the service life of seal components.
Selection should also consider installation adaptability and operational convenience. During selection, verify the chemical pump shaft diameter and seal chamber dimensions to ensure precise matching between seal components and the pump body, avoiding seal face damage from installation interference. Prioritize modular pump mechanical seals; their disassembly and assembly do not require dismantling core pump components, reducing maintenance labor hours. In practical selection, it is recommended to conduct simulation calculations based on working condition parameters and collaborate with seal manufacturers to complete material compatibility and structural rationality verification, eliminating blind selection.
In summary, the core of pump mechanical seals selection lies in achieving precise matching of medium characteristics, working condition parameters, and seal structures. By scientifically selecting corrosion-resistant and high-temperature-resistant materials and optimizing seal structure and auxiliary system configurations, the risks of corrosion and high-temperature leakage can be effectively avoided, ensuring the long-term stable operation of chemical pumps and providing core technical support for safe chemical production.
