How to Install and Maintain Mechanical Seals?

Installation and Maintenance of Mechanical Seals

一、Standard Installation Procedures

1. Pre-Installation Preparation: Inspect the seal for damage (e.g., scratches on seal faces, aging of elastomers) and clean all components (shaft, sleeve, seal chamber) to remove impurities. Verify that shaft runout is within 0.1mm and the surface roughness of the shaft/sleeve mating with the seal is Ra 0.2–0.4μm.
2. Assembly Operations: Apply a thin layer of compatible lubricant (consistent with the medium) to the seal faces, elastomers, and shaft surface. Install elastomers first, then press the seal cartridge evenly onto the shaft without hammering to avoid damaging the seal faces. Ensure the seal is axially positioned correctly and the compression amount of the spring meets the manufacturer’s specifications (typically 2–5mm).
3. Post-Installation Check: Rotate the shaft manually to confirm smooth operation without jamming. Connect the cooling/barrier fluid system (if applicable) and check for leaks in the pipeline.

二、Key Maintenance Measures

1. Regular Inspection: Periodically monitor the leakage rate (should be ≤5ml/h for liquids), operating temperature (seal chamber temperature should not exceed the medium temperature by 20°C), and abnormal noises. Record operating data to track performance changes.
2. Lubrication and Cooling Management: Maintain stable supply of cooling/barrier fluid, ensuring the flow rate and temperature meet requirements (e.g., cooling water temperature ≤35°C). Avoid dry running of the seal, which can cause instantaneous burnout of the seal faces.
3. Replacement Criteria: Replace the seal immediately if leakage exceeds the limit, the seal face is severely worn/cracked, or elastomers show swelling, aging, or cracking. After replacement, conduct a test run under low load to confirm normal operation.
4. Storage Requirements: Unused seals should be stored in a dry, clean environment at room temperature, avoiding direct sunlight and contact with corrosive substances. Seal faces should be protected with anti-corrosion film to prevent damage.