Characteristics and Maintenance of Ceramic Lined Valve

Characteristics and Maintenance of Ceramic Lined Valve

Ceramic lined valves are made of high-tech new ceramic structural materials for valve sealing components and vulnerable parts, which improves the wear resistance, corrosion resistance, and sealing performance of valve products, significantly extending the valve's service life. The use of ceramic lined valves can greatly reduce the frequency of valve maintenance and replacement, improve the safety and stability of the supporting equipment operating system, and save equipment repair costs.

Advantages of ceramic lined valves:

1. Simple structure, convenient manufacturing, and maintenance.
2. Small working stroke, short opening and closing time.
3. Good sealing performance, low friction between sealing surfaces, and longer service life.

Disadvantages of ceramic lined valves:

1. High fluid resistance, requiring greater force to open and close the valve.
2. Not suitable for media with particles, high viscosity, or tendency to coke formation.
3. Poor regulating performance.

Characteristics of ceramic lined valves:

1. All parts in contact with the medium are made of structural ceramic materials, which have excellent chemical stability and hardness (Rockwell hardness HRC90), second only to diamond. Therefore, this valve has excellent wear resistance, corrosion resistance, erosion resistance, good thermal insulation, and low thermal expansion.

2. The ball is manufactured using advanced grinding equipment and processes, with high roundness accuracy and good surface quality. After grinding with the valve seat, it can achieve excellent sealing performance by utilizing the self-lubricating properties of ZrO2 ceramics.

3. Overcomes the disadvantages of metal hard-sealed ball valves, such as easy leakage, large torque, and corrosion resistance issues of sealing surfaces.

4. Excellent wear resistance of ceramics ensures the durability and long service life of the valve, which is 2-4 times longer than titanium alloy valves and monel valves.

5. Suitable for high-hardness particle media or corrosive media with soft particles, ceramic lined valves have significant advantages and are suitable valves for such media.

How to Extend the Lifespan of Ceramic Lined Valves?

1. Cleaning Pipelines to Prolong Lifespan:
Welding slag, rust, solidified slag, iron wires, cloth strips, etc., in the pipeline can cause blockages or jamming at the throttling port or in the arc polishing machine guide, leading to valve core fracture. This often occurs during the initial operation of newly commissioned systems or after major maintenance. In such cases, disassemble the valve for cleaning, remove debris, and if the sealing surface is damaged, it should be ground. Also, open the bottom plug to flush away debris and rinse the pipeline. Before commissioning, fully open the control valve and allow the medium to flow for a period before normal operation.

2. Increase Opening Degree to Extend Lifespan:
When starting to use ceramic control valves, operate them at the maximum opening degree, such as 80%. This way, the initial erosion and wear caused by impurities in the pipeline occur outside the damaged part of the valve core. After clearing impurities from the pipeline, adjust the opening of the control valve to slightly larger than normal. As the fluid damages the valve core, the flow increases, and the opening of the arc polishing machine decreases accordingly. This continuous damage gradually closes the valve until the entire valve core is fully utilized, until the valve core and sealing surface are damaged beyond use.

3. Increase Diameter to Improve Lifespan:
By calculating the CV value formula, determine the correct CV to select the appropriate valve diameter (standard). Under the same flow rate conditions, the smaller the valve diameter, the faster the fluid flow velocity, and the more severe the erosion of the valve core and sealing components. It is recommended that users appropriately increase the valve diameter within the range of free adjustment of the opening to reduce wear.

4. Change the Structure of the Arc Polishing Machine to Improve Lifespan:
Ceramic control valves initially adopted a two-piece structure, which was later changed to the commonly used three-piece structure for a more rational valve structure. This structure has dual valve seats, thus having dual sealing characteristics. Also, when selecting ceramic ball valves, choose valves with a slope transition design, which can reduce fluid impact.

5. Transfer Damage Locations to Improve Lifespan:
Transfer severe damage to secondary locations to protect the sealing surfaces and throttling surfaces of the valve core and seat. Typically, the most severely eroded and fastest fluid velocity areas in ceramic ball valves are below the fluid inlet. For the current three-piece structure of ceramic ball valves, the core can be reversed for use, allowing one core to be used four times at the inlet, extending the valve's lifespan fourfold.

Proper use and maintenance of Ceramic lined valves are paramount to extending their lifespan.