May 23, 2015 – Valve and Pump Facts

Plains All American Pipeline utilizes technology and tools customarily available to our industry to operate, inspect and maintain our pipeline systems.

Plains’ 11-mile Line 901 pipeline is equipped with one check valve and three remotely-controlled, motor-operated valves.

A check valve is an inline device that automatically closes if oil were ever to reverse flow in the pipeline due to an abnormal flow condition.

The remotely-controlled, motor-operated valves are operated by our Midland Control Center via a Supervisory Control and Data Acquisition (SCADA) system which provides real-time operating information to our pipeline controllers.

The Midland Control Center monitors flows and pressures on a 24-hr basis and has the ability to remotely start and stop pumps and open and close motor-operated valves.

Pumps move the oil through the pipeline and are equipped with controls that are programmed to automatically shut down under certain operating conditions.

All of our pump stations are equipped with pressure monitoring devices and will automatically shut-down if operating pressures exceed maximum discharge or minimum suction thresholds.

There has been some commentary questioning why the pipeline did not have automatic shut-off valves. While these types of valves may be appropriate for use in the movement of compressible gases, they are not considered to be appropriate for use in the movement of incompressible fluids. Closing a valve on an operating pipeline increases the pressure. Use of these types of valves could have the unintended consequence of pressuring the line beyond its maximum operating pressure.

It is much safer for controllers who understand the hydraulics of a crude oil pipeline to shut it down using a planned sequence of steps than for a computer to automatically close a valve on oil that is traveling in a confined space under high pressure.

Other than reverse flow check valves, to our knowledge, the use of automatic shutoff valves on liquid pipelines in the United States is a very uncommon (or rare) due to the over pressure risk.