Line pack is a procedure for allowing more gas to enter a pipeline than is being withdrawn, thus increasing the pressure, “packing” more gas into the system, and effectively creating storage. The “packed” gas can subsequently be withdrawn when needed. A useful method of meeting short term (hourly or diurnal) peak demand requirements. In some areas, where there is a particularly high peak demand, a series of additional pipeline loops may be laid near the entry to a network to provide additional line pack. Such systems are effectively a modern version of the traditional Gas Holder.