Views: 0 Author: Site Editor Publish Time: 2026-02-27 Origin: Site
When facing leakage issues, many front-line maintenance personnel often do not know where to start. Blindly disassembling or replacing the seal not only wastes time and costs but also may miss the optimal troubleshooting window and even exacerbate equipment damage. This article will accurately break down the core causes of mechanical seal leakage, provide a "from simple to complex, rapid positioning" troubleshooting process, and offer actionable solutions to help you efficiently handle leakage problems and reduce downtime losses.
| Leakage Category | Proportion | Core Causes |
| Improper Installation (Most Common) | 40% | 1. Inadequate cleaning of seal faces, with impurities trapped between faces damaging fit; 2. Unreasonable adjustment of compression (excessive compression causes wear, insufficient compression leads to leakage); 3. Excessive misalignment, resulting in uneven force on seal faces; 4. Incorrect installation or mismatched material of auxiliary seals; 5. Uneven force on fastening bolts, causing gland tilt. |
| Fluctuating Operating Conditions & Mismatch | 30% | 1. Incorrect matching of media characteristics (failure to select appropriate materials for particle-containing or highly corrosive media); 2. Sudden changes in temperature/pressure, causing uneven thermal expansion and contraction of seal faces; 3. Abnormal speed or excessive shaft movement, damaging fit accuracy; 4. Failure of flushing system, leading to scaling and wear on seal faces. |
| Seal Component Damage/Aging | 15% | 1. Wear, chipping, or poor material quality of friction pairs; 2. Aging, cracking, or deformation of auxiliary seals; 3. Fatigue, fracture, or rust of springs; 4. Purchase of low-quality seals with insufficient machining precision. |
| Inadequate Maintenance | 10% | 1. Lack of regular inspections, leading to accumulated hidden dangers; 2. Failure to replace seals when they reach service life, forcing continued operation; 3. Brutal maintenance operations, damaging components; 4. Media contamination, with impurities accelerating wear on seal faces. |
| Equipment Malfunction | 5% | 1. Wear, ovality, or bending of pump shaft; 2. Deformation or wear of seal chamber; 3. Excessive equipment vibration, causing unstable fit of seal faces. |
| Troubleshooting Step | Time Consumed | Core Operation | Key Check Points |
| Visual Inspection | 2 minutes (no shutdown required) | Observe leakage location and volume; inspect surrounding components | 1. Determine leakage direction based on leakage location; 2. Preliminary locate the cause through leakage volume/state; 3. Touch the gland to check temperature, and inspect flushing pipelines and bolts. |
| Operating Parameter Check | 3 minutes (before shutdown) | Check equipment operating parameters to identify fluctuating conditions | 1. Check if media parameters match seal selection; 2. Check if temperature/pressure exceed design limits; 3. Check if speed and vibration are normal; 4. Check if pump shaft movement exceeds the allowable range. |
| Simple Testing | 3 minutes (after shutdown) | Bolt tightening, flushing system test, manual shaft turning, etc. | 1. Tighten bolts and observe if leakage decreases; 2. Unclog flushing pipelines and test effectiveness; 3. Manually turn the shaft to check for jamming; 4. Inspect the condition of exposed auxiliary seals. |
| Disassembly Inspection | 2 minutes (precise positioning) | Disassemble the seal and inspect core components | 1. Check if seal faces are worn or carbonized; 2. Check if auxiliary seals are aged or damaged; 3. Check if spring force is uniform; 4. Check if the sleeve, shaft, and seal chamber are intact. |
| Leakage Cause Category | Specific Issue | Corresponding Solution |
| Leakage Caused by Improper Installation (Easiest to Resolve) | Impurities on Seal Faces | Disassemble the seal, wipe the seal faces, sleeve, and chamber with cotton cloth and alcohol to remove impurities and burrs, then reinstall to ensure cleanliness. |
| Unreasonable Compression | Adjust the gland position according to the seal design requirements to ensure the compression amount is 2-5mm (subject to manufacturer's parameters). After adjustment, manually turn the shaft to confirm uniform resistance. | |
| Excessive Misalignment | Adjust the concentricity between the shaft and seal sleeve, correct the perpendicularity between the chamber and shaft. Minor shaft bending can be straightened. | |
| Incorrect Installation of Auxiliary Seals | Replace scratched/deformed components with materials matching the operating conditions. Apply a small amount of grease during installation to avoid scratching. | |
| Uneven Bolt Force | Tighten the bolts evenly diagonally in 2-3 steps to ensure the gland is flat and not tilted. | |
| Leakage Caused by Fluctuating Operating Conditions & Mismatch | Incorrect Media Matching | Particle/fiber-containing media: Replace with wear-resistant structure + cemented carbide + silicon carbide friction pairs; Highly corrosive media: Replace with perfluoroelastomer auxiliary seals + silicon carbide friction pairs. |
| Sudden Temperature/Pressure Changes | Optimize process operations to avoid sudden changes. For high-temperature conditions, install or repair cooling devices to control the seal face temperature within the design range. | |
| Abnormal Speed/Excessive Shaft Movement | Adjust the speed to the normal range, fasten the sleeve, and adjust the bearings. If shaft movement exceeds the limit, replace the bearings or shaft. | |
| Flushing System Failure | Unclog pipelines, inspect the flushing pump to ensure sufficient flushing volume. For particle-containing media, install a filter in the flushing pipeline. | |
| Leakage Caused by Seal Component Damage/Aging | Friction Pair Damage | Replace worn components with materials matching the operating conditions (silicon carbide for high-temperature conditions, cemented carbide for particle-containing conditions). |
| Auxiliary Seal Aging | Replace aged/cracked components with materials matching the media and temperature (fluororubber for high temperatures, perfluoroelastomer for strong corrosion). | |
| Spring Failure | Replace fatigued/broken/rusted springs with matching models to ensure uniform spring force. | |
| Low-Quality Seals | Replace with qualified brand products. For bulk purchases, request material testing reports and factory inspection reports. | |
| Leakage Caused by Inadequate Maintenance | Lack of Regular Inspections | Establish a system: Inspect the seal condition weekly and clean flushing pipelines and filters monthly. |
| Delayed Seal Replacement | Reserve spare parts in advance according to the service life (1-3 years, depending on operating conditions) and replace them promptly when they expire. Do not force continued operation. | |
| Improper Maintenance Operations | Standardize disassembly and assembly processes to avoid brutal operations. Strictly control installation accuracy according to standards during installation. | |
| Media Contamination | Install a filter at the equipment inlet and clean it regularly to prevent impurities from entering the chamber. | |
| Leakage Caused by Equipment Malfunction | Pump Shaft Wear/Bending | For minor wear, repair the shaft surface by electroplating or spraying; for severe wear or bending, replace the pump shaft. |
| Seal Chamber Deformation | Repair or replace the chamber to ensure the mounting surface is flat and dimensions are accurate. | |
| Excessive Equipment Vibration | Fasten the base/bearings, correct the levelness. For severe vibration, inspect the impeller/rotor and repair equipment faults. |