Generally, the following drawings shall be included: general layout, process flow chart, PID diagram, layout of each unit, elevation, pipeline layout, list of equipment and materials, longitudinal section of pipeline, instructions, etc. If necessary, some details should be added, such as the processing details of the outlet weir of the sedimentation tank and the connection details of the inlet and outlet pipes of the water pump.

After you get the drawings, you must review them yourself. If you don't understand them, you can have them reviewed. At home, the qualifications of many first-class design institutes are also problematic. Double confirmation can be foolproof.