Pressure piling
Pressure piling describes phenomena related to combustion of gases in a tube or long vessel. As the flame front propagates along the tube, the unburned gases ahead of the front are compressed, and hence heated. The amount of compression varies depending on the geometry and can range from twice to eight times the initial pressure. Where multiple vessels are connected by piping, ignition of gases in one vessel and pressure piling may result in a deflagration to detonation transition and very large explosion pressure.