Which methods are usually used to connect pipes together?

The correct answer identifies methods commonly utilized for connecting pipes, emphasizing types that ensure secure and durable connections. Welding is a prevalent method that joins metal pipes by melting the ends together, resulting in a strong and permanent bond suitable for high-pressure applications. Glands refer to mechanical devices used to connect pipes while allowing for some flexibility or movement, which is crucial in systems that may experience thermal expansion. Flanges are flat pieces attached to the ends of pipes, allowing them to be bolted together securely, making this method versatile for connecting various pipe sizes and materials. Together, these methods are widely recognized in various industries for their effectiveness in creating reliable pipe connections under different operational conditions.

While other methods listed may also be valid, such as screws and compression fittings for smaller pipes or specific applications, the combination of welding, glands, and flanges in this context underlines reliable and robust solutions for pipe connection across different industries.