Black powder, a mix of iron sulfides, oxides, and other material can represent a serious threat to
the integrity of pipelines by plugging pipelines, eroding compressor components, plugging
instrumentation and pipeline drips, preventing valid in-line inspection by In-Line Inspection
(ILI) pigs, and causing damage to customer equipment. However, black powder may not be a
problem until it starts to move due to fluid velocity. The velocity to cause movement of dry black
powder in pipelines is presented for black powder in gas pipelines. Once black powder starts to
move, it will continue to move until the flow rate is reduced or the gas is compressed. Examples
of black powder problems in the field are presented. Movement of dry black powder can be
partially controlled by using corrosion inhibitors, while powder wet with compressor oil requires
higher velocities.
KEY WORDS: Black Powder, Iron Sulfide, Iron Carbonate, Iron Oxide, pipelines, gas pipelines, flow velocity,
erosion-corrosion, pigging, cleaning