What defines a Mechanical Joint in piping connections?

• A. A connection using glue and solvent cement
• B. A threaded connection
• C. A welded joint
• D. A compression around the center line without caulking, threading, soldering, solvent cementing, brazing or welding

Answer: (D)

A Mechanical joint is defined by sealing and holding together pipe sections purely through mechanical means that compress around the centerline, using components like a gasket and gland or clamp, without any caulking, threading, soldering, solvent cementing, brazing, or welding. This is why the description that specifies compression around the center line and explicitly excludes those other joining methods fits best. It captures the essence of a mechanical joint: a seal created by tightening components to compress a gasket around the pipe, not by adhesive bonds or heat-based fusion.

Adhesives (glue or solvent cement) rely on chemical bonding to seal, so they aren’t mechanical joints. A threaded connection depends on threads to hold and seal, which is a different joining method. A welded joint uses heat to fuse materials together, which again is not mechanical.