Jiaxing Burgmann Mechanical Seal Co., Ltd. Jiashan King Kong Branch

A mechanical seal is designed to prevent fluid leakage between rotating equipment components, such as pumps, mixers, and reactors. However, leakage can occur due to many different reasons, including improper installation, incorrect seal selection, operating conditions, or equipment problems. Understanding the causes of mechanical seal leakage helps users improve equipment reliability and extend seal service life. 1. Dry Running of the Seal Faces One of the most common causes of mechanical seal failure is dry running. Mechanical seals rely on a thin lubricating film between the rotating face and stationary face. When the seal operates without sufficient liquid lubrication, the sealing faces generate excessive heat, causing: * Seal face damage * Cracking of carbon faces * Overheating * Rapid wear To avoid dry running, always ensure proper fluid circulation before starting the equipment. ⸻ 2. Improper Installation Incorrect installation is another major reason for seal leakage. Common installation problems include: * Damaged O-rings during assembly * Incorrect installation dimensions * Dirty sealing faces * Improper spring installation * Misalignment between shaft and seal The sealing faces must be clean, flat, and correctly aligned during installation. ⸻ 3. Wrong Mechanical Seal Selection A mechanical seal must be selected according to the actual operating conditions. Important factors include: * Temperature * Pressure * Rotational speed * Medium characteristics * Chemical compatibility For example, a standard carbon/ceramic seal may not be suitable for high-temperature chemical applications. In such cases, materials like silicon carbide, tungsten carbide, or special elastomers may be required. ⸻ 4. Excessive Vibration and Shaft Movement Equipment vibration can damage mechanical seals. Possible causes include: * Shaft misalignment * Bearing wear * Pump imbalance * Excessive shaft runout Continuous vibration can cause uneven wear of sealing faces and lead to leakage. ⸻ 5. Damaged or Incorrect Elastomers O-rings and rubber components provide secondary sealing. Leakage may occur when elastomers are: * Chemically attacked * Swollen or hardened * Cracked due to high temperature * Incorrectly selected Choosing the correct elastomer material, such as FKM, EPDM, or PTFE, is critical. ⸻ 6. Contaminated Sealing Medium Solid particles in the fluid can damage the sealing faces. Examples: * Sand * Metal particles * Crystallized materials * Slurry particles For abrasive media, special seal designs such as hard face combinations or double mechanical seals may be required. ⸻ 7. Incorrect Operating Conditions Mechanical seals may leak when actual operating conditions exceed design limits. Problems include: * Pressure exceeding seal rating * Temperature exceeding material limits * Running below minimum flow * Frequent start and stop cycles Always check that the seal operating conditions match the original design requirements   Jiaxing Burgmann Mechanical Seal Co., Ltd Email: doris@mechanicalseal.com.cn Mob: 86-15381220188 WhatsApp: 8615381220188 Website: www.industrial-mechanicalseals.com Add: A-5 Wanyangzhongchuangcheng, Ganyao Town, Jiashan county, Jiaxing, Zhejiang, China. 314107

1. Check the Mechanical Seal Before Installation * Inspect all seal components carefully to ensure there is no damage, contamination, or deformation. * Verify that the seal model, size, materials, and operating parameters match the reactor requirements. 2. Cleanliness During Installation * Keep the working area clean and dust-free during installation. * Clean the shaft, seal chamber, and all sealing surfaces before assembly. * Avoid touching the seal faces with dirty hands or tools. 3. Shaft and Equipment Inspection * Check the shaft or sleeve surface for scratches, corrosion, or excessive wear. * Ensure the shaft runout and alignment are within the specified tolerance. * Confirm that the seal chamber dimensions meet the mechanical seal requirements. 4. Installation of Seal Faces * Handle the seal faces carefully to prevent scratches or impact damage. * Do not apply excessive force during installation. * Ensure the rotating and stationary faces are correctly aligned and fully seated. 5. O-Ring and Elastomer Installation * Check O-rings and elastomer parts for damage before installation. * Use a suitable lubricant compatible with the process medium when installing O-rings. * Avoid twisting, cutting, or overstretching elastomer components. 6. Spring and Rotating Parts Assembly * Ensure springs move freely without blockage. * Confirm the correct installation direction of rotating components. * Tighten all screws evenly according to the recommended torque. 7. Flushing and Cooling System * For high-temperature reactor applications, ensure the cooling or heating circulation system is properly connected. * Confirm that flushing liquid is clean and flowing before operation. * Avoid dry running of the mechanical seal. 8. Vacuum and Pressure Conditions * For vacuum reactor applications, check the seal design is suitable for negative pressure operation. * Perform a pressure and leakage test before starting the equipment. 9. Initial Operation Check * Rotate the shaft manually before startup to confirm smooth movement. * Start the reactor at low speed and monitor for abnormal vibration, noise, or leakage. * Check seal temperature and operating conditions during the first hours of operation. 10. Maintenance Recommendations * Regularly inspect leakage, vibration, temperature, and lubrication conditions. * Replace worn sealing components in time to prevent equipment damage. * Always follow the mechanical seal manufacturer’s installation instructions. Important: A mechanical seal is a precision component. Proper installation, clean working conditions, and correct operating parameters are essential to achieve reliable sealing performance and long service life   Jiaxing Burgmann Mechanical Seal Co., Ltd Email: doris@mechanicalseal.com.cn Mob: 86-15381220188 WhatsApp: 8615381220188 Website: www.industrial-mechanicalseals.com Add: A-5 Wanyangzhongchuangcheng, Ganyao Town, Jiashan county, Jiaxing, Zhejiang, China. 314107

A typical mechanical seal includes: 1. Seal Faces The seal faces are the most important working parts. Common materials include carbon, silicon carbide, tungsten carbide, and ceramic. The selection depends on the operating conditions, such as pressure, temperature, speed, and the type of medium. 2. Secondary Seals O-rings, elastomers, or bellows are used to prevent leakage between the seal components and the equipment shaft. 3. Spring System The spring provides the necessary closing force to maintain contact between the seal faces during operation. 4. Metal Parts Metal components provide mechanical support and protection. Materials such as stainless steel, alloy steel, and special alloys are commonly used for corrosion resistance.   Jiaxing Burgmann Mechanical Seal Co., Ltd Email: doris@mechanicalseal.com.cn Mob: 86-15381220188 WhatsApp: 8615381220188 Website: www.industrial-mechanicalseals.com Add: A-5 Wanyangzhongchuangcheng, Ganyao Town, Jiashan county, Jiaxing, Zhejiang, China. 314107

1. Pre-Work Safety Preparation * ☐ Confirm equipment is shut down and isolated (Lockout/Tagout applied) * ☐ Ensure zero pressure in pump and piping system * ☐ Drain and flush pump casing completely * ☐ Verify fluid is safe to handle (chemical/MSDS check) * ☐ Wear proper PPE (gloves, goggles, face shield, protective clothing) * ☐ Prepare clean working area to avoid contamination ⸻ 2. Pre-Disassembly Inspection * ☐ Record pump operating condition (temperature, pressure, leakage history) * ☐ Check seal leakage rate and location * ☐ Inspect coupling alignment condition (if accessible) * ☐ Mark relative positions of pump casing, gland, and shaft sleeve * ☐ Take photos before dismantling for reference ⸻ 3. Mechanical Seal Removal * ☐ Remove coupling guard * ☐ Disconnect coupling and check shaft movement * ☐ Remove pump cover / back pull-out assembly * ☐ Loosen gland plate bolts evenly in cross pattern * ☐ Carefully slide gland and seal assembly off shaft * ☐ Avoid scratching shaft sleeve or shaft surface * ☐ Remove stationary and rotating seal components separately * ☐ Keep seal faces clean and protected from impact * ☐ Inspect for abnormal wear pattern before cleaning ⸻ 4. Inspection After Removal * ☐ Check seal faces for cracks, heat marks, or scoring * ☐ Inspect elastomers (O-rings, gaskets) for swelling or hardening * ☐ Check shaft/sleeve for wear grooves or corrosion * ☐ Verify gland plate flatness and damage * ☐ Inspect bearing condition if axial/radial movement is suspected * ☐ Identify root cause of failure (dry running, misalignment, contamination, etc.) ⸻ 5. Preparation Before Installation * ☐ Clean all components with approved solvent * ☐ Ensure shaft/sleeve is smooth and burr-free * ☐ Replace worn sleeve or damaged components * ☐ Confirm correct seal type and material compatibility * ☐ Check installation dimensions against OEM drawing * ☐ Lightly lubricate O-rings (use compatible lubricant only) * ☐ Ensure seal faces are clean and not touched by hands ⸻ 6. Mechanical Seal Installation * ☐ Install stationary seat squarely into gland or housing * ☐ Ensure no tilt or misalignment during insertion * ☐ Install rotating seal unit onto shaft carefully * ☐ Avoid damaging elastomers during sliding * ☐ Position seal at correct installation length (per datasheet) * ☐ Tighten gland bolts evenly in cross pattern * ☐ Verify shaft rotation is smooth after assembly * ☐ Ensure correct spring compression / seal setting distance ⸻ 7. Reassembly of Pump * ☐ Reinstall pump casing and align components properly * ☐ Reconnect coupling and perform alignment check (laser/dial indicator) * ☐ Reinstall coupling guard * ☐ Confirm all bolts are torqued to specification * ☐ Reconnect flush / quench / barrier systems (if applicable) ⸻ 8. Pre-Start Checks * ☐ Verify pump is filled and fully primed * ☐ Confirm no dry running condition exists * ☐ Check seal support system pressure (if dual seal) * ☐ Ensure venting is complete * ☐ Rotate shaft manually to confirm no binding * ☐ Check instrument readings (pressure, temperature, flow) ⸻ 9. Start-Up Monitoring * ☐ Start pump and observe leakage level (initial slight leakage may occur) * ☐ Monitor vibration and noise * ☐ Check seal area temperature rise * ☐ Confirm stable operation within first 30–60 minutes * ☐ Inspect for abnormal leakage continuously * ☐ Record final operating parameters ⸻ 10. Post-Start Follow-Up * ☐ Re-check alignment after thermal stabilization * ☐ Verify seal chamber pressure stability * ☐ Confirm no abnormal wear signs after 24–48 hours * ☐ Log installation details for maintenance records   Jiaxing Burgmann Mechanical Seal Co., Ltd Email: doris@mechanicalseal.com.cn Mob: 86-15381220188 WhatsApp: 8615381220188 Website: www.industrial-mechanicalseals.com Add: A-5 Wanyangzhongchuangcheng, Ganyao Town, Jiashan county, Jiaxing, Zhejiang, China. 314107