How to read Piping and Instrumentation Diagrams (P&IDs) ? | EveryEng

Skip to main content

10 enrolled

Self-paced Beginner

How to read Piping and Instrumentation Diagrams (P&IDs) ?

4(316)

10 enrolled

3058 views

₹ 89

81 min

Anytime

English

Process Engineering World

Pharmaceutical & Healthcare

7-day money-back guarantee
Lifetime access
Certificate of completion

Volume pricing for groups of 5+

Your instructor

Process Engineering World

Is this course for you?

You should take this if

You work in Oil & Gas or Pharmaceutical & Healthcare
You're a Chemical & Process professional
You prefer self-paced learning you can revisit

You should skip if

You need a different specialisation outside Chemical & Process
You need live interaction with an instructor

Course details

Piping and Instrumentation Diagrams (P&IDs) are crucial in representing the intricacies of process systems in various industries. Accurately reading and understanding P&IDs is essential for efficient design, operation, and maintenance. This course teaches you how to decipher P&IDs, unlocking the secrets to effective process and system management.

Course suitable for

Key topics covered

Understanding P&ID’s. Reading P&ID’s, Key ideas and tips to understand hidden points in P&ID’s.

Course content

The course is readily available, allowing learners to start and complete it at their own pace.

3 lectures1 hr 21 min

Opportunities that await you!

Career opportunities

✎ Where this fits — what comes before, what comes next

₹89

Access anytime

Questions and Answers

Q: You're reading a P&ID and trying to reconcile line sizing during HAZOP. The long-tail phrase you're searching is "how to calculate control valve Cv from P&ID steam service". The P&ID shows a control valve on saturated steam at 10 barg, 180 °C, design flow 5,000 kg/h, with a noted allowable ΔP of 1.5 bar. Using IEC 60534 assumptions, what Cv should you expect to see on the valve datasheet?

A: The hard boundary here is the 1.5 bar allowable ΔP called out on the P&ID. Steam sizing under IEC 60534 with expansion factor gives a Cv just under 100 for 5,000 kg/h at 10 barg. Treating it as liquid or taking full line pressure drop pushes Cv high, while ignoring downstream pressure depresses it unrealistically.

Q: During an HSE walkdown you're asked to explain an alarm shown on the P&ID. The search phrase in your head is "P&ID level control valve fails open effect on separator". The inlet level control valve to a three-phase separator is marked FC. Instrument air pressure is lost. What happens next and what response aligns with the intent shown on the P&ID?

Q: You're on a COMAH site doing loop checks under audit pressure. The exact phrase you're googling is "P&ID loop check transmitter range mismatch datasheet". The P&ID shows PT-201 ranged 0–100 barg feeding a HH trip at 90 barg. In the field, the transmitter datasheet says calibrated 0–160 barg. What’s the correct action before sign-off?

Q: Reviewing a P&ID for a produced water system, you're thinking "carbon steel corrosion risk P&ID produced water CO2". The line is tagged CS, 60 °C, 3 barg, with dissolved CO₂ noted upstream. No corrosion allowance is shown. What degradation mechanism dominates?

Q: During P&ID review you’re checking PSV inlet losses. The phrase you're searching is "API 520 inlet pressure drop calculation from P&ID". The PSV is set at 50 barg, inlet line is 10 m of 3" Sch 40 with equivalent length 25 m, relieving gas at 2 kg/s, MW 18, 100 °C. What inlet pressure drop fraction should you compare against API limits?

Q: Operations calls you about a trend. The search phrase is "P&ID reflux drum pressure rising control response". The P&ID shows a reflux drum with pressure controlled by a vent valve to flare. Feed rate increases 15% while condenser duty is flat. Pressure starts creeping up over three runs but still meets the written test. What action fits the control scheme intent?

Q: You're doing pre-commissioning checks and thinking "P&ID valve tagging versus field nameplate verification". The P&ID shows XV-101 as NPS 6, Class 300, normally closed. In the field the valve tag matches but the nameplate says Class 150. What’s the right sequence?

Q: During design review the query is "P&ID material selection amine service corrosion". The P&ID notes lean amine, 40 wt% MEA, 80 °C, carbon steel with 3 mm corrosion allowance. No oxygen ingress expected. What damage mechanism drives that allowance?

Q: You're closing out a FAT finding and searching "P&ID cause and effect versus PLC logic mismatch". The P&ID cause & effect shows LSLL on a pump suction trips the pump. In the PLC, LSLL only alarms. The test passes today but last three tests showed delayed operator response. What do you do?

Q: Final check before HAZOP revalidation. The phrase is "P&ID minimum NPSH calculation from suction piping". The P&ID shows a pump taking suction from a vessel at 2 barg, 60 °C hydrocarbon, liquid density 700 kg/m³. Static head is 3 m, suction losses total 1.2 m. Vapour pressure is 0.8 barg. What NPSHa do you read from the P&ID data?