P&ID

How it is used

The key document for design, construction, HAZOP, operation and maintenance. Engineers review, mark up, redline and 'walk down' P&IDs (check them against the real plant). Said as 'P and I D' or 'P and ID'.

Example sentences

1. The bypass valve is missing from the P&ID, so please add it in the next revision.

2. We'll go through the P&ID node by node in the HAZOP tomorrow.

Common collocations

• P&ID review
• mark up the P&ID
• as-built P&ID
• P&ID walkdown

Related terms

• process flow diagramA drawing that shows the main equipment of a plant, how the streams connect them and the key operating data such as flows, temperatures and pressures.
• HAZOPShort for hazard and operability study: a structured team review of a P&ID, section by section, using guide words to find deviations that could cause harm or operating problems.
• control loopA set of parts that work together to hold one process variable at its setpoint: a sensor and transmitter, a controller and a final element such as a control valve.
• transmitterA field instrument that measures a value such as pressure, temperature, level or flow and sends it as an electrical signal, often 4–20 mA, to the control system.
• control valveAn automatic valve that opens and closes in small steps on a signal from a controller, so that flow, pressure, level or temperature stays at the setpoint.

More terms: Process Control and Instrumentation

• setpoint
• feedback control
• PID controller
• flowmeter
• DCS