In the US alone, there are thousands of miles of pipelines carrying crude oil and other petroleum products to destinations throughout the 48 mainland states. While the product begins its journey with major force, the product loses forward momentum over time and distance.
To overcome this, pumping stations are positioned throughout the length of the pipeline to adjust the pressure, pump the product along the line and monitor flow and other information about the transmittal of the product. (In pipeline systems carrying natural gas, similar stations are located throughout the line to help push the product along, but they are called compressor stations.)
Pipeline pumping stations also increase the through-put of the pipeline. In other words, if a pipeline needs to be able to have a higher through-put capacity, another pipeline pumping station may be added to overcome the challenge.
Pipeline pumping stations may be strategically located for their proximity to other equipment, or a pumping station may be constructed to help push the product through a more difficult section of the pipeline, such as over a mountain range.
There are a number of different types of pumps that can be found in the pumping stations, including a full head pump, which is a two-stage pump with the impellers in a series, consisting of one inlet and one outlet. Also, there are half stage pumps with the impellers in parallel and including two inlets and two outlets. Half stage pumps are capable of handling twice the flow of full head pumps, but only produce half the pressure rise. Pumping stations may also house booster pumps, which move product from the storage tanks at the station into the main line.
Pumping stations also contain safety equipment and house on-staff safety personnel to overcome any problems along the pipeline route. Additionally, pumping stations are often the location for launching pipeline pigs to help clear the line and inspect the pipeline for any corrosion or other damage from the inside.
Pumping Stations at Work: Trans-Alaska Pipeline
Traveling a distance of more than 800 miles, the Trans-Alaska pipeline transports oil produced on the North Slope's Prudhoe Bay to the Port of Valdez in southern Alaska for shipment via tankers to US markets.
This massive pipeline boasts 11 pumping stations, although the line was designed to house 12. Coming online in 1977, the pipeline first had eight pumping stations working, which picked up to 11 by 1980 as through-put ramped up. After daily capacity has dropped over time, the pipeline now has five operating stations with one reserve station.
Pumping Station 1 has a pumping capacity of 420,000 barrels of oil per day, and Pumping Station 5 has a through-put capacity of 150,000 barrels of oil per day. All the other stations house a pumping capacity of 55,000 barrels of oil per day.
At each pumping station, there are anywhere from 10 to 25 personnel that work there, and these employees work 12-hour days in either a one week on, one week off shift or a two weeks on, two weeks off shift.