Fluoroplastic lined centrifugal pumps are widely used in chemical, pharmaceutical, and environmental protection industries due to their excellent corrosion resistance and reliability. However, even such advanced equipment can face mechanical seal leakage issues. Understanding the causes of mechanical seal leakage is crucial for taking effective preventive and remedial measures. This article provides an in-depth analysis of the common causes of mechanical seal leakage in fluoroplastic lined centrifugal pumps and offers corresponding solutions.

Common Causes of Mechanical Seal Leakage

1. Seal Face Wear

The seal faces of mechanical seals are subject to high-speed rotation, leading to friction and eventual wear. Once the seal faces wear out, the sealing effectiveness is greatly reduced, resulting in fluid leakage.

Solution:Regularly inspect and replace worn seal faces to ensure their smoothness and sealing performance.

2. Shaft or Shaft Sleeve Wear

Wear on the pump shaft or shaft sleeve can also affect the proper functioning of the mechanical seal. When the shaft or shaft sleeve wears out, the gap between the moving and stationary rings changes, causing seal failure.

Solution:Regularly check the wear condition of the shaft and shaft sleeve, and replace them as necessary.

3. Improper Installation

The quality of the mechanical seal installation directly affects its sealing performance. If the installation is not carried out according to the operational specifications, issues such as uneven seal faces and uneven force on the seal components may occur, leading to leakage.

Solution:Ensure that the mechanical seal installation is performed by professional personnel and strictly follow the installation specifications to avoid uneven force on the seal components.

4. Corrosion of the Medium

Fluoroplastic lined centrifugal pumps are mainly used for conveying highly corrosive media. If the sealing material is not resistant to the medium's corrosion, it will chemically react over time, causing seal failure.

Solution:Select appropriate sealing materials based on the chemical properties of the medium to ensure the seals have good corrosion resistance.

5. Improper Operating Conditions

Operating the pump outside its design conditions, such as frequent start-stop operations and overload running, will impose additional stress and wear on the mechanical seal, increasing the risk of leakage.

Solution:Avoid frequent start-stop operations and overload running, and ensure the pump operates within its design conditions to reduce stress on the mechanical seal.

6. Bearing Damage

Bearing damage can cause shaft misalignment, which in turn affects the normal working state of the mechanical seal, causing changes in the gap between the moving and stationary rings, resulting in leakage.

Solution:Regularly inspect and maintain the bearings to ensure their normal operation and prevent seal issues caused by bearing damage.

Methods for Detecting Mechanical Seal Leakage

1. Visual Inspection

Visual inspection can reveal obvious leakage signs, such as fluid seepage outside the pump body. Visual inspection is simple and straightforward, making it a common initial method for detecting leakage issues.

2. Pressure Testing

Performing pressure testing on the pump can detect whether the sealing system has leakage. Pressure testing can provide more precise leakage information and is a commonly used detection method.

3. Vibration Analysis

Vibration analysis can detect abnormal vibration conditions during pump operation, thereby identifying potential issues with bearings and the sealing system. Vibration analysis requires specialized equipment and technicians.

Measures to Prevent and Resolve Mechanical Seal Leakage

1. Regular Maintenance and Inspection

Regularly maintain and inspect the pump, checking the wear condition of the seal faces, shaft, and shaft sleeve, and promptly replacing worn components to ensure the proper functioning of the sealing system.

2. Selecting Appropriate Sealing Materials

Choose corrosion-resistant and wear-resistant sealing materials based on the chemical properties of the medium and operating conditions to ensure the long-term stable operation of the mechanical seal.

3. Strict Installation Specifications

Ensure that mechanical seal installation is carried out by professional personnel, strictly following installation specifications to avoid leakage issues caused by improper installation.

4. Optimizing Operating Conditions

Avoid frequent start-stop operations and overload running, ensuring the pump operates within its design conditions to reduce stress and wear on the mechanical seal.

Mechanical seal leakage is a common fault in fluoroplastic lined centrifugal pumps. By thoroughly analyzing the causes of leakage and taking effective preventive and remedial measures, the risk of leakage can be significantly reduced, and the pump's service life can be extended. We hope this analysis and the provided suggestions can offer practical guidance for your pump system, ensuring stable operation under various working conditions.