The transport of gas in gas pipelines is similar to the transport of oil but differs as to the operating conditions and the equipment used. Smaller pipelines lead from a gas field to a gasworks where the gas is cleared of impurities such as water, sulfur, toxic gas, sulfides, and dioxides. After this cleansing process at the gasworks, the gas is fed into the distance pipeline. In contrast to oil pipelines, compressors along the route generate sufficient pressure in the pipeline.