What may be used to make a joint between copper tubing and threaded galvanized steel pipe

Mechanical seals are typically used in rotating equipment to prevent fluid leaks, but they are not suitable for joining two distinct types of pipe materials like copper and galvanized steel. They rely on a different mechanism than what is required for a permanent and secure joint in plumbing applications.

Brazing involves joining metals by melting a filler metal above 450°C, which can work for copper to copper or similar metals but is not the most practical method for connecting copper to galvanized steel. This method also requires a clean and fluxed surface to be effective, which may not always be feasible.

Welding typically involves melting the base metals to create a joint, which is not advisable when joining copper and galvanized steel due to their differing melting points and properties. This process may lead to distortion or damage to one or both materials, making it unsuitable for plumbing applications.