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 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.