Skip to content
Sun, Oct 11, 2026 / Ideas for a clearer worldINDEPENDENT INSIGHTS · PRACTICAL TOOLS · EXPLAINERS
Sign in
EXPLOREArtificial IntelligencePersonal FinancePythonStartupsMechanical EngineeringDigital MarketingCybersecurity
basic / August 14, 2021

Basic engineering documents

Pipe rack study sketches:                These are prepared taking into account requirements of piping, electrical & instrument cable trays to be routed between various plant areas. These documents are used by civil, piping, electrical and instrument group to prepare detailed construction drawings. Study piping layouts: Prepared to show routing of critical process lines which could affect […]

By · August 14, 2021 · 3 min read

Pipe rack study sketches:               

These are prepared taking into account requirements of piping, electrical & instrument cable trays to be routed between various plant areas.

These documents are used by civil, piping, electrical and instrument group to prepare detailed construction drawings.

Study piping layouts:

Prepared to show routing of critical process lines which could affect functioning of plant. This document reviewed by process licensor and forms basis of detailed piping layout drawings.

Piping specifications:

These documents specifies in detail all piping items required for the plant.

Various piping items required for a particular duty condition, depending on type of fluid; line pressure & temperature are listed under one specification class.

●        Utility flow diagram (UFD)

●        This document is similar to P&ID’s

●        Prepared based on utility summary

●        Prepared based on utility summery furnished by process group

●        Shows utility generation and distribution in the plant.

Line numbering and line list

All process and utility lined appearing in P&ID’s and UFD’s are given unique serial numbers on these documents the operating, design and test conditions, insulation & painting requirements are listed on line list.

Critical line list

All line requiring stress/vibration analysis etc. Are listed in this document

Piping Layouts

Document required to develop piping layout:

1) Equipment layouts  

2) Process P&ID’s 

3) Utility P&ID’S  

4) Line designation list  

5) Piping specification  

6) Equipment data sheets /vendor drawings  

7) Civil drawings  

8) Inline instrument details  

9) Insulation requirements

Following points shall be kept in mind while developing piping layouts

Process requirements e.g.

Slopes, vents & drains, barometric leg for vacuum lines

●        Instrument requirements e.g.

●        Straight length for flow measurement

●        Location of control valves, safety valves,

●        PLS, TIS, etc.

●        Safety requirements

●        Operations & maintenance

●        Accessibility

●        Service /hose stations, safety showers

Piping layouts is required by site for construction to prepare isometrics & into instrument group for hook-ups.

Piping layouts must consider

●        Process requirements operations & maintenance requirements area classification

●        Safety requirements factory inspector’s requirements TAC

●        Requirements civil requirements erection / dismantling requirements future provisions.