As with any surface, the inner walls of our pipelines are not perfectly smooth which leads to some friction when a product like natural gas flows through them. Even a small amount of friction will cause some pressure loss after the natural gas has passed through the pipeline for many miles. A pipeline company must install compressors along the pipeline to re-pressure the natural gas so it may continue to flow. Compressor stations are typically installed at intervals of 30 to 70 miles (approximately 48 to 112 kms) along the pipeline.