Necessity and Effect Analysis of Mechanical Seal for Water Pump Modification

In the operation of water plants, the sealing performance of water pumps is directly related to the efficiency and safety of the equipment. With continuous technological advancements, more and more water plants are choosing to replace traditional packing seals with mechanical seals for water pumps to improve overall performance and reduce maintenance costs. This article will analyze the background, process, and effects of a certain water plant's water pump seal upgrade.

Background of the Upgrade: Choosing Mechanical Seals for Water Pumps

After replacing all intake pumps with single-stage double-suction horizontal clean water pumps, a certain water plant found several issues with using packing seals. Firstly, the shaft seal leakage was severe, and adjusting the packing gland was difficult. Secondly, replacing the packing required removing the pump cover, increasing labor and intensity of maintenance. Additionally, the quality of packing cutting was significantly influenced by human factors, making seal quality difficult to control. The wear of stainless steel shaft sleeves was also quite severe, leading to high replacement costs. To solve these problems, the water plant decided to replace the packing seal with a mechanical seal for water pumps to reduce work intensity and improve pump operation efficiency.

Theoretical Analysis: Advantages and Disadvantages of Mechanical Seals for Water Pumps

Compared to packing seals, mechanical seals for water pumps offer several advantages. Firstly, the sealing performance of mechanical seals is reliable, with long-term operation leakage being only 1% of that of packing seals. Secondly, the mechanical seals for water pumps have a long service life, usually reaching 1-2 years or more in oil-water media. Their friction power consumption is also significantly reduced, only being 10% to 50% of that of packing seals. In addition, mechanical seals are not easily worn, have long maintenance cycles, and possess good shock resistance.

However, mechanical seals for water pumps also have their disadvantages, such as more complex structures, high processing requirements, and relatively troublesome installation and replacement. These disadvantages require operators to have a certain level of technical proficiency.

Upgrade Process: Installation of Mechanical Seals for Water Pumps

During the upgrade, the water plant adopted a phased installation plan. The main steps involved in the upgrade included:

1. Removing the original pump's packing and accessories, and cleaning the seal chamber.

2. Reprocessing worn shaft sleeves and using 304 stainless steel material.

3. Installing a baffle sleeve and seal gland to ensure the stability of the mechanical seal.

4. Blocking the original cooling water inlet of the packing seal and redirecting the cooling water through the seal gland's inlet.

Each step of the upgrade must be strictly followed according to technical specifications to ensure the effectiveness of the mechanical seals for water pumps.

Analysis of Upgrade Effects: Effectiveness of Mechanical Seals Application

After approximately three months of use, the effects of mechanical seals for water pumps were significant:

Reliable Sealing Performance

After the upgrade, there was no leakage at the shaft seal, no need for additional adjustments, greatly reducing the work intensity for employees and improving the hydraulic performance of the pump.

Stable Operation

The vibration of the pump compared to packing seals was not significantly different, showing that the mechanical seals performed excellently during operation.

Reduced Wear

After using mechanical seals for water pumps, there was no wear on the shaft sleeve, avoiding the decline in seal quality caused by traditional packing seals.

In terms of energy-saving effects, although the direct energy-saving effect of mechanical seals for water pumps was not significant, data on water intake unit consumption showed a decrease of about 0.5%. This indicates that mechanical seals reduced energy loss caused by casing leakage and friction to some extent.

Mechanical seals for water pumps have effectively improved the operational efficiency and equipment safety of the water plant. By reducing water leakage and wear, not only were maintenance costs reduced, but the overall performance of the water pumps also improved. In the future, the water plant can continue to promote the application of mechanical seals to further enhance the reliability and economy of the equipment.