General description Always use a JG Speedfit pipe insert when connecting Speedfit pipe to a Speedfit push-fit fitting or when connecting to a compression fitting. Inserts play a vital role in providing extra support to pipework, ensuring that the ends of the pipe are kept nice and round, and minimizing any loss of shape that can occur when cutting. Designed and manufactured in the UK, these inserts enhance sealing for a securer connection, maintain the structural integrity of the pipe connection, and help make the pipe more rigid when a side load is applied. They are suitable for hot and cold water and central heating systems.