NCCER Pipeline Ops key terms

The day-to-day activities required to move product safely through a pipeline system, including monitoring, controlling, maintaining, and documenting flow, pressure, and equipment condition along the entire route.

A staffed facility where operators watch system data and remotely adjust pumps, valves, and flow to keep the pipeline within safe operating limits and respond to alarms.

The qualified person who monitors and directs pipeline movement from the control room, making adjustments and taking emergency action to protect people, property, and the environment.

Supervisory Control and Data Acquisition, a computer system that gathers measurements from remote sites and lets controllers issue commands to pumps, valves, and other equipment.

Remote Terminal Unit, field hardware at a station or valve site that collects sensor readings and carries out control commands sent from the control room over a communications link.

Programmable Logic Controller, an industrial computer that runs local logic to start, stop, and interlock pumps, valves, and safety devices without waiting for control room instructions.

The transmission of measured values such as pressure, flow, and temperature from field locations to a remote monitoring point, usually by radio, satellite, cellular, or fiber.

Maximum Allowable Operating Pressure, the highest pressure a pipeline segment may legally and safely be operated at, set by design, code, and testing requirements.

The range of pressures, flows, temperatures, and product conditions within which a pipeline segment can run safely and reliably without exceeding design or code limits.

A rapid pressure wave caused by a sudden change in flow, such as a valve closing or pump stopping, that can exceed normal limits and damage equipment if not controlled.

A vessel or standpipe connected to a pipeline that absorbs or supplies liquid during sudden flow changes, reducing pressure spikes and protecting pumps and pipe from damage.

A device that opens automatically when pressure exceeds a set point, releasing product to protect pipe, pumps, and vessels from overpressure and then closing when pressure falls.

A condition in which pressure in a pipeline or vessel rises above its allowable limit, creating risk of failure and requiring immediate correction or protective device action.

A facility with one or more pumps that adds energy to move product along a pipeline, along with valves, meters, controls, and power equipment needed to run them.

A large pump at a station that provides the primary pressure needed to move product through the main pipeline over long distances between stations.

A pump used to raise pressure at an intermediate point or to feed another pump, helping maintain flow and pressure without being the main source of line pressure.

Formation and collapse of vapor bubbles in liquid inside a pump or pipe when local pressure drops too low, causing noise, vibration, and damage to pump parts.

Net Positive Suction Head, the margin of pressure above a liquid's vapor pressure at the pump suction, needed to prevent cavitation and keep the pump operating properly.

The pressure measured at the inlet side of a pump, which must stay high enough to keep liquid entering the pump and avoid cavitation or loss of flow.

The pressure measured at the outlet side of a pump, reflecting the energy added to the product and the resistance of the downstream pipeline system.

A valve that allows flow in only one direction and closes automatically when flow reverses, protecting pumps and equipment from backflow and limiting surge effects.

A valve installed on a pipeline to stop or start flow in a section, used for isolation during maintenance, emergencies, or segment separation.

A device that opens or closes a valve using electric, pneumatic, hydraulic, or manual power, often controlled remotely from the control room or by local logic.

A planned sequence that stops pumps, closes valves, and isolates equipment quickly to limit product release and protect people and facilities during an abnormal event.

A protective control arrangement that prevents or forces an action, such as blocking a pump start until conditions are safe, to avoid equipment damage or unsafe operation.

The process of setting, prioritizing, and responding to alarms so controllers can act on important abnormal conditions without being overwhelmed by unnecessary notifications.

Methods and systems used to identify product escaping from a pipeline, such as volume balance, pressure monitoring, and sensor-based systems, so response can begin quickly.

A leak detection method that compares the amount of product entering a pipeline segment with the amount leaving it, accounting for inventory changes, to spot unexplained losses.

A device that measures the quantity or rate of product moving through a point in the pipeline, used for custody transfer, accounting, and leak detection calculations.

The point where product changes ownership and quantity and quality are measured and documented, often requiring high-accuracy metering and sampling.

A device or method used to check and adjust a meter's accuracy by comparing its readings with a known volume under controlled conditions.

Adjusting an instrument so its readings match known reference values, keeping pressure, flow, and other measurements accurate for control and safety decisions.

A distinct quantity of product with specific properties moved through a pipeline between other products, tracked to prevent mixing and to deliver correct quality to customers.

The mixed zone where two different batches meet inside a pipeline, which must be tracked and handled so each product meets its quality specification.

Running a device called a pig through a pipeline to clean the interior, separate batches, inspect the wall, or measure conditions, using flow to push it along.

The condition of a pipeline being sound and fit for service, maintained through inspection, testing, monitoring, and repair so it does not fail or release product.

A pressure test in which a pipeline section is filled with water and pressurized above normal operating pressure to confirm strength and find leaks before service.

Using instrumented tools that travel inside a pipeline to detect corrosion, cracks, dents, and other defects so integrity can be assessed and repairs planned.

A technique that applies a small electrical current to buried pipe to reduce corrosion, extending pipeline life and helping maintain integrity.

A protective layer applied to pipe surfaces to keep moisture and chemicals away from the metal, working with cathodic protection to control external corrosion.