Drawing a diagram of the supply systems
A diagram is a picture that shows the parts of a system and how they connect, using symbols. Before drawing a diagram the system’s parts are identified and a symbol is chosen for each. A water supply diagram shows the outer pipe, inlet valve, meter, distribution pipes, taps and a hot water device. A gas diagram draws the inlet pipe, shut-off tap, gas meter and the pipe to the gas stove. An electrical diagram shows the circuit breaker, meter, residual-current device, sockets and switches with lamps. A heating diagram shows the heat source, pipes and radiators. When drawing, it is convenient to keep lines straight and not crossing, explain the symbols (a legend), and show each system in its own colour (for example water blue, heating red). A diagram is for reading and understanding only: you never connect pipes or wires yourself on its basis; specialists do that work. If dangerous places such as shut-off valves and the circuit breaker are marked on the diagram, they can be found quickly in an emergency.
Home diagram: on A3 paper draw the plan of a house or flat and mark its water, gas, electricity and heating diagrams in different colours with a legend. Mark the shut-off valves and circuit breaker separately.