For industrial PVC-C pipes of different diameters, the choice of connection method does vary. This is mainly because pipes of different diameters differ in terms of pressure resistance, fluid transmission efficiency, and ease of installation, so different connection methods are needed to accommodate these differences.

Small diameter pipes
For industrial PVC-C pipes of small diameter (e.g., pipe diameters less than or equal to 110mm), common connection methods include:
Cold melt connection (solvent bonding): This method is suitable for the connection of pipes to pipes and pipes to fittings. By cleaning the end faces of the pipes and fittings, applying a special solvent or glue, and then quickly inserting the pipe into the fitting and waiting for it to solidify, a firm and sealed connection can be formed.
Threaded connection: Suitable for situations where connections with valves, instruments and other equipment are required. By applying thread sealant to the outer surface of the pipe and then tightening the pipe fittings to the pipe, the firmness and sealing of the connection can be ensured.

Large diameter pipes
For industrial PVC-C pipes of large diameter, the commonly used connection methods are different, mainly including:
1. Welding connection: This method is suitable for occasions with high connection quality requirements, such as large pipeline systems or occasions where high-strength connections are required. By heating the pipe end faces to melt them, and then pressing the two melted pipe end faces together and cooling them to solidify, a very strong connection can be formed.
2. Flange connection: Mainly used for connections between pipes and pipes, pipes and equipment, especially in situations where they need to withstand certain pressures or temperature fluctuations. Flange connections are composed of components such as flanges, gaskets, bolts and nuts. The flanges are tightly connected together by tightening the bolts to achieve a stable connection of the pipe.

Considerations for selecting connection methods
When choosing a connection method, in addition to the pipe diameter, the following factors need to be considered:
1. Working pressure and temperature: A more secure and better sealed connection method is required in high pressure and high temperature environments.
2. Fluid properties: Corrosive fluids or special media may require specific connection methods to ensure safety.
3. Convenience of installation and maintenance: Connection methods that are easy to install and maintain can reduce construction costs and time.
4. Cost-effectiveness: The costs of different connection methods are different, and they need to be selected based on the project budget.

For industrial PVC-C pipes of different diameters, the choice of connection method needs to be comprehensively considered based on the specific situation. In practical applications, it is recommended to consult professionals or refer to relevant literature to ensure that the appropriate connection method is selected and the corresponding construction specifications are followed.