What type of joint is used to connect polybutylene plastic pipe?

The type of joint commonly used to connect polybutylene plastic pipe is a mechanical joint. Mechanical joints are designed to create a secure connection between two pieces of pipe using an external mechanism such as a clamp or a fitting that physically holds the pipes together. This type of joint is particularly appropriate for polybutylene pipe, as it allows for flexibility and accommodates the slight movements that can occur due to temperature changes or settling of the structure.

Fusion joints, while effective for certain types of thermoplastic materials, are not typically used with polybutylene pipe. These joints involve melting the plastic at the connection point, which is not a standard process for polybutylene.

Compression joints, on the other hand, are often used for softer materials, but they typically involve a fitting that compresses against the pipe, which may not provide the best long-term durability compared to mechanical joints for polybutylene pipes.

Solder joints are primarily associated with metal piping, such as copper. The process involves melting a filler metal to join the surfaces together, which is not applicable to plastic piping systems like those made from polybutylene.

Thus, the mechanical joint is the most suitable and widely recognized method for ensuring reliable connections in polybutylene piping systems.