Precommisioning 

Pipeline pre-commissioning is the process of proving the ability of a pipeline and piping systems to contain product without leaking. This product may be liquid, gaseous or multi phase hydrocarbons, water, stream, CO2, N2, Petrol, aviation fuel etc.

Pre-commissioning is the series of processes carried out on the pipeline before the final product is introduced. The process during which the pipeline is made "live" i.e. the product is put in the pipeline, is called pipeline commissioning or start-up.