NCCER Pipeline Ops flashcards
NCCER Pipeline Ops · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- MAOP
- Maximum allowable operating pressure: the highest internal pressure a pipeline may legally and safely carry under its design, code, and regulatory basis. Operating targets must stay below it.
- Normal operating pressure
- The planned steady-state pressure at which a line is routinely run. It must remain below MAOP with enough margin that surge events do not exceed the limit.
- Hydrostatic test
- Strength test using water pressure, typically 1.25 to 1.5 times MAOP held at least 8 hours for new steel line. It proves integrity and establishes the pressure basis for operations.
- Pressure surge
- Transient pressure spike caused by rapid velocity change, such as fast valve closure or pump trip. Magnitude roughly equals density times wave speed times velocity change.
- Water hammer
- Common name for surge in liquid lines: kinetic energy converts to a pressure wave when flow stops suddenly. It can exceed MAOP and damage pipe or fittings.
- Wave speed
- Speed at which a pressure wave travels in the fluid and pipe, set by fluid density, bulk modulus, pipe wall stiffness, and diameter. It drives surge magnitude.
- Valve closure time
- Time taken to stop flow through a valve. Longer closure spreads the velocity change over time and lowers the surge peak; fast closure raises it sharply.
- Batch
- A discrete volume of one product moved through the line, separated from adjacent batches by an interface. Batch scheduling keeps deliveries on spec.
- Transmix
- Mixture formed at the boundary between two batches. It is reprocessed, downgraded, or sold off-spec rather than delivered as prime product.
- Interface slug
- The buffer volume between two product batches. Operators track its position and volume so cut points separate on-spec product from transmix.
- Line fill
- The volume of product contained in the pipeline at any time. It determines how much must be injected before delivery reaches the far end.
- Packing the line
- Filling line volume before delivery begins. Packing time equals line volume divided by flow rate, so lag depends on fill volume, not pump size.
- Volume balance
- Accounting rule: injected volume minus delivered volume equals line fill change plus interface volume. Any unexplained residual signals leak, meter error, or unaccounted withdrawal.
- Mass balance leak detection
- Method comparing measured inlet and outlet flows over time. A sustained imbalance beyond instrument tolerance triggers investigation or shutdown per procedure.
- Computational pipeline monitoring
- Software model using pressure, flow, and temperature data to detect anomalies along the line. It flags deviations that simple mass balance might miss.
- Pump in series
- Pumps arranged so flow passes through each in turn. Heads add while flow stays the same, raising discharge pressure for a given rate.
- Pump in parallel
- Pumps arranged so they share the same suction and discharge headers. Flows add at a common head, increasing total throughput.
- Cavitation
- Vapor bubbles form when suction pressure drops below fluid vapor pressure, then collapse and damage pump internals. Adequate suction pressure prevents it.
- Net positive suction head
- Margin of absolute pressure above vapor pressure at the pump suction. Insufficient NPSH available versus required causes cavitation and loss of performance.
- Pump station control
- Maintaining suction and discharge pressures within limits by adjusting pump speed, throttle valves, or pump count. It protects equipment and keeps flow on target.
- Cathodic protection
- Impressed current or sacrificial anodes that shift pipe potential negative, suppressing corrosion. Target is -0.85 V or more negative versus copper-copper sulfate electrode.
- Pipe-to-soil potential
- Voltage measured between buried pipe and a reference electrode in contact with soil. It indicates whether cathodic protection is adequate at that location.
- Coating holiday
- A break or defect in pipeline coating exposing bare steel. Holidays concentrate cathodic protection current demand and are common corrosion initiation sites.
- Rectifier
- Equipment converting AC power to DC for impressed current cathodic protection. Output is adjusted to hold pipe-to-soil potential at the protection criterion.
- Block valve
- Valve used to isolate sections of line for maintenance or emergency. Its location and closure speed affect surge and how much volume is isolated.
- Check valve
- One-directional valve preventing reverse flow. It protects pumps and limits backflow after a trip, but rapid closing can contribute to surge.
- Pressure relief valve
- Device that opens at a set pressure to protect line or equipment from overpressure. Set points are coordinated with MAOP and surge analysis.
- SCADA
- Supervisory control and data acquisition system gathering pressure, flow, and status data from remote sites and letting controllers operate valves and pumps.
- Control room operator
- Person monitoring SCADA and directing line operations. They respond to alarms, adjust set points, and initiate shutdowns under written procedures.
- Pig
- Device run through a pipeline for cleaning, inspection, or batch separation. Pigging removes debris and can confirm internal condition.
- Smart pig
- In-line inspection tool carrying sensors such as magnetic flux or ultrasonic transducers. It records wall thickness and defect data for integrity assessment.
- Product specification
- Required quality limits for a delivered product, such as vapor pressure, sulfur, or flash point. Batch cuts are made so delivered volumes meet these limits.