Final answer:
The X symbol on a pipe drawing indicates where a weld type pipefitting or valve is to be installed. It represents a full penetration welded joint.
Step-by-step explanation:
The X symbol on a pipe drawing indicates where a weld type pipefitting or valve is to be installed. It is a common symbol used in engineering drawings to denote a weld joint. The X symbol usually represents a full penetration welded joint, where the two pieces of pipe or the pipe and valve are completely fused together.
For example, if there is an X symbol at a connection point between two pipes, it means that a weld joint needs to be made at that location to connect the pipes. This indicates that the two pipes should be welded together using the specified welding procedure and type of weld, as described in the pipe drawing's welding specifications.