Useful service data includes the medium and its main components, concentration, normal and maximum temperature, operating and design pressure, nominal size, connection standard, operating mode and whether throttling is required.
Also identify solids, crystallization, volatility or special cleanliness requirements. Actuated valves require power or air supply details, control signals and fail-position requirements.
The more complete the service definition, the better the basis for evaluating compatibility, construction and application limits.