Checklist for Piping & Instrumentation Engineering Drawings Review

II JAY SHRI KRISHNA II

In the intricate world of engineering design, where millimeters matter and miscommunication can lead to million-dollar mistakes, ensuring the accuracy and completeness of piping and instrumentation drawings (P&IDs) is a critical step. These drawings serve as the backbone of the engineering, procurement, and construction (EPC) process in oil & gas, chemical plants, power projects, and other industrial sectors.

This guide provides a detailed and systematic approach to reviewing engineering drawings with a focus on piping and instrumentation. Whether you are an entry-level piping designer or a senior project engineer, this checklist will help you spot missing details, reduce errors, and enhance project efficiency and safety.

_______________________________________________________

Why is P&ID Review So Important?

• P&IDs are the primary communication tool between different engineering disciplines.

• Errors in P&IDs can lead to costly rework during construction.

• Accurate P&IDs are essential for safe and efficient plant operation.

Checklist for Piping & Instrumentation Engineering Drawings Review

📌 General Drawing Information Review

1. Drawing Number, Revision Number & Issue Date

• Every drawing must have a unique identification number, revision number and issue date. Confirm that the drawing in hand is the latest version issued by the design office.

2. Issue Description & Highlighted Issue Column

• The issue description must explain the reason for issuing or revising the drawing. Ensure that the issue column is clearly highlighted and marked for visibility and audit tracking.

3. North Direction & Property Line

• The north direction arrow is essential for orientation. Verify the property line and limits are well defined, especially when coordinating with other departments.

4. Correctness of Symbols Used

• All symbols must conform to the standard legend or engineering codes used by your organization or client. Avoid using outdated or non-standard representations.

5. Comparison with Plot Plan

• Compare the drawing against the approved plot plan to ensure consistency in equipment locations, roads, buildings and pipe racks.

_______________________________________________________

📍 Location, Coordinates and Elevation

1. Location as Per Plot Plan

• Cross-check equipment and piping locations with the master plot plan to ensure correct spatial arrangement.

2. Coordinates Confirmation

• Verify that all X, Y, and Z coordinates for equipment, nozzles and foundations match the civil layout and structural grid.

3. Elevations Confirmation

• Ensure equipment elevations, nozzle centerline heights and platform levels are correctly mentioned and coordinated.

4. Check with Mechanical Department Inputs

• Confirm alignment with mechanical department inputs, including equipment specifications, orientation and access needs.

5. Verification Against Engineering Drawings

• Match P&ID and layout with mechanical, civil, instrumentation and electrical engineering drawings for integrated design assurance.

_______________________________________________________

🔧 Equipment and Nozzle Configuration

1. Nozzle Numbers & Schedule

• All nozzles should be clearly tagged with numbers matching the equipment data sheets and P&ID. Check if the nozzle schedule is attached or referenced.

2. Nozzle Orientation

• Confirm that nozzle orientations are accurate, with correct angular spacing and direction as per vendor prints or 3D model.

3. Lugs/Legs Orientation & Elevation

• Lifting lugs, support legs and brackets must be shown with orientation and elevation for correct installation.

4. Fixed and Sliding Support Location

• Clearly define all pipe supports—whether fixed, guided, or sliding—to maintain piping flexibility and reduce stress.

5. Local Platforms, Ladders & Stairways

• Verify that all maintenance platforms, access ladders and stairways are provided wherever necessary for operation or service.

6. Rotary Equipment Size and Type

• Mark the type and size of rotary equipment such as pumps and compressors. Include access and service areas.

7. Package Equipment Access Clearance

• Ensure overall dimensions and required clearances for skid or package units are maintained for installation and operation.

_______________________________________________________

🧱 Civil & Structural Coordination

1. Grid Number Confirmation

• Equipment and pipe supports must be referenced to structural grid numbers for accurate layout and construction.

2. Foundation Coordinates & Heights

• Cross-check that foundation dimensions, elevations and positions match civil GA drawings.

3. Local Support Location

• Confirm pipe support base plates and stanchion foundations are not clashing with adjacent equipment or structural elements.

4. Fouling with Nearby Foundations or Structures

• Check for interference with foundations, platforms, handrails and embedded structures.

5. Structural Interference Check

• Ensure piping does not foul with beams, columns, platforms or bracings. Allow clearance for thermal expansion and vibration.

_______________________________________________________

🔌 Instrumentation Hook-Up and Access

1. Instrumentation Hook-Up Points

• Confirm that provision is made for level, flow, pressure and temperature instruments based on P&IDs.

2. End Connection Types & Dimensions

• Check face-to-face (F/F) or end-to-end (E/E) dimensions and end connections (flanged, threaded, socket weld) for each instrument.

3. Gauge and Transmitter Viewing Direction

• Level gauges, pressure gauges and transmitters should be oriented for easy visibility and accessibility.

4. Cable Tray / Duct Routing & Support

• Review the routing of instrument cable trays or ducts, ensuring proper support and no clash with piping or structures.

5. Local Control Panel Access

• Control panels must be accessible with no obstruction to doors or operational space.

6. Analyzer Tapping Points

• Verify the locations of analyzer tappings are safe and reachable. Ensure proper isolation valves are installed.

7. Instrument Air Manifold & End Connection

• Instrument air headers should be accessible, with clear tagging and termination for end-user connection.

8. Flow Instrument Straight Length

• Ensure minimum straight run before and after flow meters (e.g., orifice plates, venturis) as specified by the manufacturer.

9. Control Valve Maintenance Space

• Leave adequate space for valve actuator removal and maintenance tasks.

10. Thermowell Accessibility

• Confirm thermowells can be installed and removed easily without dismantling nearby items.

11. Instrument Junction Boxes

• The location, height, and mounting of instrument junction boxes must support safe cabling and accessibility.

_______________________________________________________

⚡ Electrical Coordination Checklist

1. Electrical Cable Trays and Trenches

• Cable trays should not interfere with piping or supports. Check tray height, direction, and clearances.

2. Motor Junction Box Orientation

• Ensure the motor terminal box orientation does not clash with piping and is accessible for cable pulling and termination.

3. Lifting Equipment & Maintenance Provision

• Check whether lifting hooks, davit arms, or mobile crane access is provided for heavy motor/equipment removal.

4. Grounding and Bonding of Piping

• All metallic piping systems must be properly grounded and bonded in accordance with electrical grounding standards.

_______________________________________________________

✅ Final Review & Documentation

1. Mark-Up and Review Tracking

• Use standard review comments or redline markings for documentation and future reference.

2. Multidiscipline Coordination Sign-Off

• Final checklists must be signed off by all disciplines, confirming interdepartmental review has been completed.

3. As-Built Drawing Preparation

• Ensure all site changes are recorded for as-built drawing preparation post-installation.

_______________________________________________________

Conclusion: The Value of a Systematic Drawing Review

A systematic approach to reviewing piping and instrumentation drawings is not just about ticking boxes—it’s about ensuring operational reliability, safety and construction efficiency. Each element in this checklist plays a role in preventing clashes, minimizing errors and streamlining project execution.

Investing time in proper drawing verification helps avoid costly rework, ensures smoother site installation and reinforces multidisciplinary collaboration. In the long run, this leads to enhanced project outcomes, safer operations and greater client satisfaction.

So next time you're assigned to check a drawing, pull out this checklist and give your project the quality assurance it deserves. Every detail matters in engineering—and now you’ve got the ultimate guide to make sure nothing gets missed.

_______________________________________________________

✅ Your downloadable checklist PDF is ready!

📥Click below to download the full checklist PDF for Piping and Instrumentation Engineering Drawings Review:

👉 Download Checklist PDF

📝 Prepared By: Know Piping Engineering

_______________________________________________________

🚀 For more insights, check out these related posts:

Site Selection for a Plant: Key Considerations

Piping GA Drawing: A Comprehensive Guide Series - Part 4: Drawing Content & Dimensioning Guidelines

Plot Plan: Essential Guide to Industrial Plant Layout

Piping Interview Preparation: Site Selection, Plot Plans & GA Drawings

Equipment Layout: An Effective Industrial Arrangement

Piping Design Checklist for Accurate Engineering Drawings

Checklist for Civil & Structural in Piping Layouts

Checklist for Piping Engineers: Plot Plan and Equipment Layout

Please like, message and share if you feel all my blogs are beneficial, useful or helpful for you and for other also.

Thank you so much for following my blog…!! 🙏

See you all in the next coming blogs till then keep exploring piping field……!!

Have a great day today.... Keep smiling 😀 and God Bless You all…!!

To be continue……