Plumbing and Piping Plans

The vector stencils library "UML communication diagrams" contains 23 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"... communication diagrams use the free-form arrangement of objects and links as used in Object diagrams. In order to maintain the ordering of messages in such a free-form diagram, messages are labeled with a chronological number and placed near the link the message is sent over. Reading a communication diagram involves starting at message 1.0, and following the messages from object to object." [Communication diagram. Wikipedia]
The example "Design elements - UML communication diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.