Piping and instrumentation diagramFrom Wikipedia, the free encyclopedia

Piping and instrumentation diagram of pump with storage tank. Symbols according to EN ISO 10628 and EN 62424.

A piping and instrumentation diagram/drawing (P&ID) is a diagram in the process industry which

shows the piping of the process flow together with the installed equipment and instrumentation.

Contents

  [hide] 

1   Contents and Function

2   List of P&ID items

3   Identification and Reference Designation

4   Symbols of chemical apparatus and equipments

5   See also

6   External links

[edit]Contents and Function

An example of a P&ID.

A piping and instrumentation diagram/drawing (P&ID) is defined by the Institute of Instrumentation and

Control as follows:

1. A diagram which shows the interconnection of process equipment and the instrumentation used

to control the process. In the process industry, a standard set of symbols is used to prepare

drawings of processes. The instrument symbols used in these drawings are generally based

on International Society of Automation (ISA) Standard S5. 1.

2. The primary schematic drawing used for laying out a process control installation.

P&IDs play a significant role in the maintenance and modification of the process that it describes. It is

critical to demonstrate the physical sequence of equipment and systems, as well as how these systems

connect. During the design stage, the diagram also provides the basis for the development of system

control schemes, allowing for further safety and operational investigations, such as the hazard and

operability study (HAZOP).

For processing facilities, it is a pictorial representation of

Key piping and instrument details

Control and shutdown schemes

Safety and regulatory requirements

Basic start up and operational information

[edit]List of P&ID items

Instrumentation and designations

Mechanical equipment with names and numbers

All valves and their identifications

Process piping, sizes and identification

Miscellanea - vents, drains, special fittings, sampling lines, reducers, increasers and swagers

Permanent start-up and flush lines

Flow directions

Interconnections references

Control inputs and outputs, interlocks

Interfaces for class changes

Computer control system input

Identification of components and subsystems delivered by others

[edit]Identification and Reference Designation

The P&ID is used for the identification of measurements within the process. Identification letters for

measurements are based on Standard ANSI/ISA S5.1 and ISO 14617-6:

First-Letter

Measurement

A Analysis

B Burner, Combustion

C User's Choice (usually Conductivity)

D User's Choice (usually Density)

E Voltage

F Flow

G User's Choice

H Hand

I Current

J Power

K Time, Time Schedule

L Level

M User's Choice

N User's Choice (usually Torque)

O User's Choice

P Pressure

Q Quantity

R Radiation

S Speed, Frequency

T Temperature

U User's Choice (usually Alarm Output)

V Vibration, Mechanical Analysis

W Weight, Force

X User's Choice (usually on-off valve as XV)

Y Event, State, Presence

Z Position, Dimension

For reference designation of any equipment in industrial systems the standard IEC 61346 (Industrial

systems, installations and equipment and industrial products — Structuring principles and reference

designations) can be applied. For the function Measurement the reference designator B is used, followed

by the above listed letter for the measured variable.

For reference designation of any equipment in a power station the KKS Power Plant Classification

System can be applied.

[edit]Symbols of chemical apparatus and equipments

Below are listed some symbols of chemical apparatus and equipment normally used in a P&ID, according

to DIN 30600 and ISO 14617.

Symbols of chemical apparatus and equipment

PipeThermally insulated pipe

Jacketed pipe

Cooled or heated pipe

Jacketed mixing vessel (autoclave)

Half pipe mixing vessel

Pressurized horizontal vessel

Pressurized vertical vessel

PumpVacuum pump or compressor

Bag Gas bottle

Fan Axial fan Radial fan Dryer

Packed column

Tray column

FurnaceCooling tower

Heat exchanger

Heat exchanger

CoolerPlate & frame heat exchanger

Double pipe heat exchanger

Fixed straight tubes heat exchanger

U shaped tubes heat exchanger

Spiral heat exchanger

Covered gas vent

Curved gas vent

(Air) filter Funnel

Steam trapViewing glass

Pressure reducing valve

Flexible pipe

ValveControl valve

Manual valve

Back draft damper

Needle valve

Butterfly valve

Diaphragm valve

Ball valve

[edit]See also

Commons:Category:Chemical engineering symbols  - A list of P&ID symbols in SVG format

Process flow diagram

[edit]External links

How to read P&IDs

Hazard and operability studyFrom Wikipedia, the free encyclopedia

Look up Hazop in Wiktionary,

the free dictionary.

A hazard and operability study (HAZOP) is a structured and systematic examination of a planned or existing

process or operation in order to identify and evaluate problems that may represent risks to personnel or

equipment, or prevent efficient operation. The HAZOP technique was initially developed to analyze chemical

process systems, but has later been extended to other types of systems and also to complex operations and to

software systems. A HAZOP is a qualitative technique based on guide-words and is carried out by a multi-

disciplinary team (HAZOP team) during a set of meetings.

Contents

[hide]

1 Method

o 1.1 Outline

o 1.2 Parameters and guide words

2 Team

3 History

4 References

5 Further reading

6 See also

[edit]Method

[edit]Outline

The method applies to processes (existing or planned) for which design information is available. This

commonly includes a process flow diagram, which is examined in small sections, such as individual items of

equipment or pipes between them. For each of these a design Intention is specified. For example, in a

chemical plant, a pipe may have the intention to transport 2.3 kg/s of 96% sulfuric acid at 20°C and a pressure

of 2 bar from a pump to a heat exchanger. The intention of the heat exchanger may be to heat 2.3 kg/s of 96%

sulfuric acid from 20°C to 80 °C. The HAZOP team then determines what are the possible

significant Deviations from each intention, feasible Causes and likely Consequences. It can then be decided

whether existing, designed safeguards are sufficient, or whether additional actions are necessary to reduce risk

to an acceptable level.

When HAZOP meetings were recorded by hand they were generally scheduled for three to four hours per day.

For a medium-sized chemical plant where the total number of items to be considered is 1200 (items of

equipment and pipes or other transfers between them) about 40 such meetings would be needed.[1] Various

software programs are now available to assist in meetings.

[edit]Parameters and guide words

The key feature is to select appropriate parameters which apply to the design intention. These are general

words such as Flow, Temperature, Pressure, Composition. In the above example, it can be seen that variations

in these parameters could constitute Deviations from the design Intention. In order to identify Deviations, the

Study Leader applies (systematically, in order) a set of Guide Words to each parameter for each section of the

process. The current standard[2] Guide Words are as follows:

Guide Word Meaning

NO OR NOT Complete negation of the design intent

MORE Quantitative increase

LESS Quantitative decrease

AS WELL AS Qualitative modification/increase

PART OF Qualitative modification/decrease

REVERSE Logical opposite of the design intent

OTHER THAN Complete substitution

EARLY Relative to the clock time

LATE Relative to the clock time

BEFORE Relating to order or sequence

AFTER Relating to order or sequence

(Note that the last four guide words are applied to batch or sequential operations.) These are therefore

combined e.g. NO FLOW, MORE TEMPERATURE, and if the combination is meaningful, it is a potential

deviation. In this case LESS COMPOSITION would suggest less than 96% sulfuric acid, whereas OTHER

THAN COMPOSITION would suggest something else such as oil.

The following table gives an overview of commonly used guide word - parameter pairs and common

interpretations of them.

Parameter / Guide Word More Less None Reverse As well as

Flow high flow low flow no flow reverse flowdeviating concentration

Pressure high pressure low pressure vacuum delta-p

Temperature high temperature low temperature

Level high level low level no level different level

Time too long / too latetoo short / too soon

sequence step skipped

backwards missing actions

Agitation fast mixing slow mixing no mixing

Reactionfast reaction / runaway

slow reaction no reaction

Start-up / Shut-down too fast too slow actions missed

Draining / Venting too long too short none deviating pressure

Inertising high pressure low pressure none

Utility failure (instrument air, power)

failure

DCS failure failure

Maintenance none

Vibrations too low too high none

Once the causes and effects of any potential hazards have been established, the system being studied can

then be modified to improve its safety. The modified design must then be subject to another HAZOP, to ensure

that no new problems have been added.

[edit]Team

HAZOP is normally carried out by a team of people, with roles as follows[2] (with alternative names from other

sources):

Name Alternative

Study leader Chairmansomeone experienced in HAZOP but not directly involved in the design, to ensure that the method is followed carefully

Recorder Secretary or scribe to ensure that problems are documented and recommendations passed on

Designer(or representative of the team which has designed the process)

To explain any design details or provide further information

User (or representative of those who will use it) To consider it in use and question its operability, and the effect of deviations

Specialist (or specialists) someone with relevant technical knowledge

Maintainer (if appropriate) someone concerned with maintenance of the process.

In earlier publications it was suggested that the Study Leader could also be the Recorder[3] but separate roles

are now generally recommended. A minimum team size of 5 is recommended.[4] In a large process there will be

many HAZOP meetings and the team may change as specialists are brought in for different areas, and possibly

different members of the design team, but the Study Leader and Recorder will usually be fixed. As many as 20

individuals may be involved[3] but is recommended that no more than 8 are involved at any one time.[4] Software

is now available from several suppliers to aid the Study Leader and the Recorder.

[edit]History

The technique originated in the Heavy Organic Chemicals Division of ICI, which was then a major British and

international chemical company. The history has been described by Trevor Kletz [3] [5] who was the company's

safety advisor from 1968 to 1982, from which the following is abstracted.

In 1963 a team of 3 people met for 3 days a week for 4 months to study the design of a new phenol plant. They

started with a technique called critical examination which asked for alternatives, but changed this to look

for deviations. The method was further refined within the company, under the name operability studies, and

became the third stage of its hazard analysis procedure (the first two being done at the conceptual and

specification stages) when the first detailed design was produced.

In 1974 a one-week safety course including this procedure was offered by the Institution of Chemical

Engineers (IChemE) at Teesside Polytechnic. Coming shortly after the Flixborough disaster, the course was

fully booked, as were ones in the next few years. In the same year the first paper in the open literature was also

published.[6] In 1977 the Chemical Industries Associationpublished a guide.[7] Up to this time the

term HAZOP had not been used in formal publications. The first to do this was Kletz in 1983, with what were

essentially the course notes (revised and updated) from the IChemE courses.[3] By this time, hazard and

operability studies had become an expected part of chemical engineering degree courses in the UK.[3]

[edit]References

1. ̂  Swann, C. D., & Preston, M. L., (1995) Journal of Loss Prevention in the Process Industries, vol 8, no 6,

pp349-353 "Twenty-five years of HAZOPs"

2. ^ a b British Standard BS: IEC61882:2002 Hazard and operability studies (HAZOP studies)- Application

Guide British Standards Institution. “This British Standard reproduces verbatim IEC 61882:2001 and

implements it as the UK national standard.”

3. ^ a b c d e Kletz, T. A., (1983) HAZOP & HAZAN Notes on the Identification and Assessment of

Hazards IChemE Rugby

4. ^ a b Nolan, D.P. (1994) Application of HAZOP and What-If Safety Reviews to the Petroleum, Petrochemical

and Chemical Industries. William Andrew Publishing/Noyes. ISBN 978-0-8155-1353-7

5. ̂  Kletz, T., (2000) By Accident - a life preventing them in industry PVF Publications ISBN 0-9538440-0-5

6. ̂  Lawley, H. G.,(1974) Chemical Engineering Progress, vol 70, no 4 page 45 "Operability studies and

hazard analysis" AIChE

7. ̂  Chemical Industries Association (1977) A Guide to Hazard and Operability Studies

Process flow diagramFrom Wikipedia, the free encyclopedia

A process flow diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate

the general flow of plant processes and equipment. The PFD displays the relationship

between major equipment of a plant facility and does not show minor details such as piping details and

designations. Another commonly-used term for a PFD is a flowsheet.

Contents

[hide]

1 Typical content of a process flow diagram

2 Process flow diagram examples

o 2.1 Single process unit

o 2.2 Multiple process units within an industrial plant

3 Other items of interest

4 Standards

5 Further reading

6 External links

[edit]Typical content of a process flow diagram

Some typical elements from process flow diagrams, as provided by the open source program,Dia. Click for image legend.

Typically, process flow diagrams of a single unit process will include the following:

Process piping

Major equipment items

Control valves  and other major valves

Connections with other systems

Major bypass and recirculation streams

Operational data (temperature, pressure, mass flow rate, density, etc.), often by stream references to

a mass balance.

Process stream names

Process flow diagrams generally do not include:

Pipe classes or piping line numbers

Process control instrumentation (sensors and final elements)

Minor bypass lines

Isolation and shutoff valves

Maintenance vents and drains

Relief  and safety valves

Flanges

Process flow diagrams of multiple process units within a large industrial plant will usually contain less detail and

may be called block flow diagrams or schematic flow diagrams.

[edit]Process flow diagram examples

[edit]Single process unit

The process flow diagram below depicts a single chemical engineering unit process known as an amine

treating plant:

Flow diagram of a typical amine treating process used in industrial plants

[edit]Multiple process units within an industrial plant

The process flow diagram below is an example of a schematic or block flow diagram and depicts the various

unit processes within a typical oil refinery:

A typical oil refinery

[edit]Other items of interest

A PFD can be computer generated from process simulators (see List of Chemical Process Simulators), CAD

packages, or flow chart software using a library of chemical engineering symbols. Rules and symbols are

available from standardization organizations such as DIN, ISO or ANSI. Often PFDs are produced on large

sheets of paper.

PFDs of many commercial processes can be found in the literature, specifically in encyclopedias of chemical

technology, although some might be outdated. To find recent ones, patent databases such as those available

from the United States Patent and Trademark Office can be useful.

[edit]Standards

S E L A S A , 0 3 M E I 2 0 1 1

Pipe Cut LengthUntuk kita yang berkecimpung di dunia per-piping-an pasti istilah pipes cut length (kadang juga ada yang menyebut pipes nipple) sudah familiar di telinga. Secara kasar sih pipe cut length bisa diartikan sebagai panjang potongan pipa yang ditentukan berdasarkan perhitungan sesuai isometric drawing yang kita kerjakan.

Di beberapa shipyard (termasuk perusahaan saya) perhitungan panjang potongan pipa ini dilakukan oleh orang-orang production. Jadi sejak awal pipes cut length tidak tercantum di isometric drawing yang diissue dari engineering. Di dalam isometric drawing hanya dicantumkan bill of material untuk satu gambar tersebut.

Contoh piping isometric drawing di shipyard

Seperti yang bisa dilihat di gambar diatas panjang potongan pipa tidak terlihat di dalam gambar. Yang diberikan biasanya jarak center ke center dari fitting ke fitting di kedua sisi potongan pipa tersebut. Jadi kalkulasi harus dilakukan untuk menentukan seberapa panjang kita harus memotong pipa supaya spool pipa yang dihasilkan akan sesuai dengan dimensi yang diberikan oleh isometric drawing.

Dalam melakukan hitungan ini, selain piping isometric drawing, kita menggunakan WPS dan yard standard sebagai acuan lainnya. Mungkin saya akan bahas di kesempatan berikutnya.Posted by mubarok   at 23:03 Labels: piping

Process engineeringFrom Wikipedia, the free encyclopedia

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009)

Process engineering (also called process systems engineering) focuses on the design, operation, control,

and optimization of chemical, physical, and biological processes through the aid of systematic computer-based

methods. Process engineering encompasses a vast range of industries, such as chemical, petrochemical,

mineral processing, advanced material, food, pharmaceutical, and biotechnological industries.

Contents

  [hide] 

1   Significant accomplishments

2   History

3   See also

4   References

5   External links

[edit]Significant accomplishments

Several accomplishments have been made in Process Engineering:[1]

Process design : synthesis of energy recovery networks, synthesis of distillation systems (azeotropic),

synthesis of reactor networks, hierarchical decomposition flowsheets, superstructureoptimization, design

multiproduct batch plants. Design of the production reactors for the production of plutonium, design of

nuclear submarines.

Process control : model predictive control, controllability measures, robust control, nonlinear control,

statistical process control, process monitoring, thermodynamics-based control

Process operations : scheduling process networks, multiperiod planning and optimization, data

reconciliation, real-time optimization, flexibility measures, fault diagnosis

Supporting tools: sequential modular simulation, equation based process simulation, AI/expert systems,

large-scale nonlinear programming (NLP), optimization of differential algebraic equations (DAEs), mixed-

integer nonlinear programming (MINLP), global optimization

[edit]History

Process systems engineering (PSE) is a relatively young area in chemical engineering. The first time that this

term was used was in a Special Volume of the AIChE Symposium Series in 1961. However, it was not until

1982 when the first international symposium on this topic took place in Kyoto, Japan, that the term PSE started

to become widely accepted.

The first textbook in the area was “Strategy of Process Engineering” by Dale F. Rudd and Charles C. Watson,

Wiley, 1968. The Computing and Systems Technology (CAST) Division, Area 10 of AIChE, was founded in

1977 and currently has about 1200 members. CAST has four sections: Process Design, Process Control,

Process Operations, and Applied Mathematics.

The first journal devoted to PSE was "Computers and Chemical Engineering," which appeared in 1977. The

Foundations of Computer-Aided Process Design (FOCAPD) conference in 1980 in Henniker was one of the

first meetings in a series on that topic in the PSE area. It is now accompanied by the successful series on

Control (CPC), Operations (FOCAPO), and the world-wide series entitled Process Systems Engineering. The

CACHE Corporation (Computer Aids for Chemical Engineering), which organizes these conferences, was

initially launched by academics in 1970, motivated by the introduction of process simulation in the chemical

engineering curriculum.

There are currently about 80 academics in the PSE area in the US, and a listing of these faculty can be found

in http://cepac.cheme.cmu.edu/pse1.html. A very large fraction of the faculty in the PSE area can be traced

back to Professor Roger W.H. Sargent from Imperial College, one of the pioneers in the area. PSE is an active

area of research in many other countries, particularly in the United Kingdom, several other European countries,

Japan, Korea, and China.

Since 1992 Europe hosts the annual ESCAPE meeting (European Symposium of Computer Aided Process

Engineering). Each produces proceedings—e.g., see Comput. Chem. Engng., Vol. 21 Supplement (1997) for

the Proceedings of the joint PSE ‘97/ESCAPE 7 meeting held in 1997.