PFD & PID Eng Toolbox Internet

PROCESS DIAGRAM

Block Flow Diagram, Process

Flow Diagram and P & ID

BFD - Block Flow Diagram

• Block Flow Diagram (BFD): – Schematic illustration of the major process

– The block (rectangles) represent a unit operation.

• The blocks are connected by straight lines which represent the process flow streams – which flow between the units.

– may be mixtures of liquids, gases and solids flowing in pipes or ducts, or solids being carried on a conveyor belt

Rules for Clear BFD

• Rules should be followed for clear, easy to understand & unambiguous BFD – unit operations (eg. mixers, separators, reactors, distillation

columns & heat exchangers) usually denoted by a simple block.

– groups of unit operations may be noted by a single block.

– process flow streams flowing into and out of the blocks are represented by neatly drawn straight lines.

– the direction of flow of each streams must be indicated by arrows.

– flow streams should be numbered sequentially in a logical order.

– unit operations (i.e., blocks) should be labeled.

– where possible the diagram should be arranged with upstream units on the left and downstream units on right

Small and simplified BFD

example

Uhde Ammonia Plant Block Diagram

Amine Absorption System

PFD - Process Flow Diagram

• The Process Flow Diagram - PFD, a schematic illustration of the system

• PFD or SFD (System Flow Diagram ) – shows the relationships between the major

components in the system.

– tabulate process design values for the components in different operating modes, typical minimum, normal and maximum.

– does not show minor components, piping systems, piping ratings and designations

What are in the PFD

• A PFD should include – Process Piping

– Major equipment symbols: names and identification numbers

– Control valves and valves that affect operation of the system

– Interconnection with other systems

– Major bypass and recirculation lines

– System ratings & operational values (eg. minimum, normal & maximum of flow, temperature and pressure)

– Composition of fluids

What is NOT in the PFD

• System Flow Diagrams should not include:

– pipe class

– pipe line numbers

– minor bypass lines

– isolation and shutoff valves

– maintenance vents and drains

– relief and safety valve

– code class information

– seismic class information

Example of small and simplified PFD

Example of PFD

P&ID - Piping and

Instrumentation Diagram

• A P&ID, is a schematic illustration of functional relationship of piping, instrumentation and system equipment components

• P&ID shows all of piping including – the physical sequence of branches, reducers, valves,

– equipment,

– instrumentation and control interlocks

• The P&ID are used to design & operate the process system

What are in a P&ID

1. Instrumentation and designations

2. Mechanical equipment with names and numbers

3. All valves and their identifications

4. Process piping, sizes and identification

5. Miscellaneous - vents, drains, special fittings, sampling lines, reducers, increasers and swagers

6. Permanent start-up and flush lines

7. Flow directions

8. Interconnections references

9. Control inputs and outputs, interlocks

10. Interfaces for class changes

11. Seismic category

12. Quality level

13. Annunciation inputs

14. Computer control system input

15. Vendor and contractor interfaces

16. Identification of components and subsystems delivered by others

17. Intended physical sequence of the equipment

A P&ID should include

This figure depict a very small and

simplified P&ID:

What IS NOT included

• A P&ID should not include:

– Instrument root valves

– control relays

– manual switches

– equipment rating or capacity

– primary instrument tubing and valves

– pressure temperature and flow data

– elbow, tees and similar standard fittings

– extensive explanatory notes

ADAPTIVE CONTROL OF FEED LOAD

CHANGES IN ALCOHOL

FERMENTATION http://www.scielo.br/scielo.php?pid=S010466321997000400012&script=sci_arttext

Oil system

Symbols used in Piping & Instrumentation Diagrams..

Symbols used in Piping & Instrumentation Diagrams..

Symbols used in Piping & Instrumentation Diagrams..

Symbols used in Piping & Instrumentation Diagrams..