KESELAMATAN DAN KESIHATAN PEKERJAAN (KAS3501)

Semester II 2014/2015

Group 7

Presentation date : 1 april 2015

NO.MATRI

C

NAME

UK29510 MASITAH BINTI RANI

UK29551 LIM XIN YI

UK29512 ILANI BINTI ZAMRI

UK29526 ZULFUAZ BINTI RAMSAH

UK29514 NUR SAADIAH BINTI ZAINI

Hazard and Operability Studies (HAZOP)

What is HAZOP??

A formal procedure to identify hazards

in a chemical process facility.

Systematic, comprehensive, effective,

flexible and well accepted.

Identify all the possibilities where

processes and operation can go

wrong.

For large process, the studies could

take months of biweekly meetings to

complete.

Purpose and objective of HAZOP

• HAZOP identifies potential hazards , failures and operability problems.

• Its use is recommended as a principal method by professional institutions and legislators on the basis of proven capabilities for over 40 years.

• It is most effective as a team effort consists of plant and prices designers, operating personnel, control and instrumentation engineer etc.

• It encourages creativity in design concept evaluation.

• Its use results in fewer commissioning and operational problems and better informed personnel, thus confirming overall cost effectiveness improvement.

• HAZOP reports are an integral part of plant and safety records and are also applicable to design changes and plant modifications, thereby containing accountability for equipment and its associated human interface throughout the operating lifetime

• Necessary changes to a system for

eliminating or reducing the probability of

operating deviations are suggested by the

analytical procedure.

• HAZOP provides a necessary

management tool and bonus in so far that

it demonstrates to insurers and inspectors

evidence of comprehensive thoroughness.

HAZOP MethodologyThe HAZOP analysis process is executed in four phases as illustrated

below:

Definition Phase

Begins with preliminary identification of risk assessment team

members.

HAZOP is intended to be a cross-functional team effort and

relies on specialists (SMEs) from various disciplines with

appropriate skills and

experience who display intuition and good judgment.

HAZOP should always be carried out in a climate of positive

thinking and frank discussion.

The risk assessment team must identify the assessment

scope carefully in order to focus effort.

HAZOP Team Composition

A Leader (Chairman) - the person who leads and

facilitates the HAZOP study by asking questions of the

team and encourage team to draw conclusion.

Secretary (Recorder) - the person who records the

discussions (worksheet) and produce final report.

• Team members - who represent of each of the key

disciplines involved in the facility such as Process

design, Operations, Control & Instrument, Safety, etc.

Team members provide essential inputs and discussions

to HAZOP study as per their knowledge and experience

of the process under study

HAZOP Team

HAZOP Team

Process/ Chem Eng.

Mechanical/Electrical/

Civil Eng.

Control & Instrument

Eng.

Plant Manager

Plant Superinten

dent

Safety Eng.

Supervisor

Senior technician

Lab Chemist

Preparation Phase

The Preparation Phase typically includes the following activities:

Identifying and locating supporting data and information

Identification of the audience and users of the study outputs

Project management preparations

(ex: scheduling meetings, transcribing proceedings, etc.)

Consensus on template format for recording study outputs

Consensus on HAZOP guide words to be used during the study

Once the HAZOP guide words are selected, the Examination Phase may begin.

Documents Needed for HAZOP

Study For Preliminary HAZOP

Process Flow Sheet ( PFS or PFD )

Description of the Process

For Detailed HAZOP

Piping and Instrumentation Diagram ( P & ID )

Process Calculations

Process Data Sheets

Instrument Data Sheets

Interlock Schedules (Cause and Effect Chart)

Layout Requirements

Hazardous Area Classification

Description of the Process

Incident Records (for existing plant HAZOP)

Modification Records (for existing plant HAZOP)

Process information required for

HAZOP study

Process flow diagram (PFD) Piping and Instrumentation

Diagram (P&ID’s)

MSDS

Mass and energy balances Report

Process

simulation

data

Examination Phase

The Examination Phase begins with identification of all elements (parts or steps) of the system or process to be examined.

For example:

Physical systems may be broken down into smaller parts as necessary

Processes may be broken down into discrete steps or phases

Similar parts or steps may be grouped together to facilitate assessment

The HAZOP guide words are then applied to each of the elements. (not all combinations of guide words and elements are expected to yield sensible or credible deviation possibilities)

Documentation & Follow-up

Phase The documentation of HAZOP analyses is often facilitated by

utilizing a template recording form as detailed in IEC Standard

61882.

Risk assessment teams may modify the template as necessary

based on factors such as:

Regulatory requirements

Need for more explicit risk rating or prioritization

Company documentation policies

Needs for traceability or audit readiness

Other factors

A typical HAZOP recording template is shown on the following slide

HAZOP Recording Template

Example

HAZOP

PROCEDURE

Start

Divide the plant

into various study

nodes or units

Take one

unit or study

node at a

moment

Compare the study

node with the unit

of Information

Base

Expert

INFORMATION

BASE

Is unit

matching

?

Yes

Apply guide

words

Analyze the causes

and consequences

of the deviation

drawn from the

INFORMATION

BASE

Add or remove

causes and

consequences due

to special behavior

of unit

Are all

deviation

s over?

No

No

YesAre all

study

nodes

over?

No

Yes

Prepare HAZOP

report

Stop

HAZOP PROCEDURE

1. Begin with detailed and up to date process

info.

2. Divide into separate units

and perform the HAZOP study for each unit.

3. Choose a study node for

the selected unit.

4. Provide brief description of

the function/design intention of the

study node.

5. Pick a process

parameter.

HAZOP Procedure

cont’..

6. Apply guide words/deviations

to the process parameter to

suggest possible deviations.

7. For each deviations, determine

possible causes and note any

protective systems.

8. Evaluate the consequences of the deviations (if

any).

9. Recommend action.

10. Record all information (in HAZOP form).

HAZOP Procedure cont’..

11. Repeat step 5 through 9 until

all applicable guide words have been

applied on the chosen process

parameter.

12. Repeat step 4 through 11

until all applicable process

parameters have been

considered for the given study

node

13. Repeat steps 2 through 12 until all study nodes have

been considered for

the given section

14. Process to the next section

and repeat steps 2 through

13 until all sections have

been considered for

the process plant.

15. HAZOP study complete.

A P&ID for Phosgene

reactor

A reactor

as the unit

What is unit?

What is node?

NODE: Concentrate on one location in

the process

Coolin

g coils

as

node 1Stirrer

as

node 2

Function of the study node

Study node

• Cooling coils

• stirrer

Function/design intention

• To remove excessive energy of reaction

• To promote mixing of reactants

Process parameter

• Flow

• Temperature

• Agitation

Common HAZOP Analysis

Process Parameters

Process Parameters

Flow

Pressure

Temperature

Level

Reaction

Speed

Time

pH

Toxicity

Mixing

HAZOP Guide WordsGuide Words

• NO or NOT

• MORE

• LESS

• AS WELL AS

Meanings

• The complete negation of intention

• Quantitative increase

• Quantitative decrease

• Qualitative increase

Comments

• No part of the designintention is achieved, but nothing else happen

• Applies to quantities such as flow rate and temperature and to activities such as heating and reaction.

• Applies to quantities such as flow rate and temperature and to activities such as heating and reaction.

• All the design and operating intentions are achieved along with some additional activity, such as contamination of process stream.

HAZOP Guide Words cont’

Guide Words

• PART OF

• REVERSE

• OTHER THAN

• SOONER THAN

Meanings

• Qualitative decrease

• Logical opposite of intention

• Complete substitution

• Too early or in the wrong order

Comments

• Only some of the design intentions are achieved, some are not.

• Most applicable to activities such as flow or chemical reaction. Also applicable to substances, for example, poison instead of antidote.

• No part of the original intention is achieved- the original intention is replaced by something else.

• Applies to process steps or actions.

HAZOP Guide Words cont’

Guide Words

• LATER THAN

• WHERE ELSE

Meanings

• Too late or in the wrong order

• In additional locations

Comments

• Applies to process steps or actions.

• Applies to process locations, or locations in operating procedures.

Advantages Disadvantages

Provide complete identification of

hazards from operational upsets,

operational procedures (SOPs) and

equipment failures

Potentially identify hazards

independent of the risk (as HAZOP is

not a risk assessment process)

Fewer commissioning and operational

problems

Need a team with experience

judgment

Less down time Time consuming and expensive

Improved product quality and less

waste is produced

Requires detailed design drawing to

perform the full study

Employees’ confident in the safety of

the process

Focuses on one-event causes of

deviation only

Better informed personnel

Could be used as evidence of

comprehensive thoroughness to

insurers and inspectors

Adv & dis-adv HAZOP

References

1. Guides, R. M. (n.d.). Manufacturing Technology Committee – Risk Management Working Group. Retrieved March 26, 2015, from Risk Management Training Guides:http://images.alfresco.advanstar.com/alfresco_images/pharma/2014/08/21/347197a7-b965-45fe-ac72-daeeb77baa21/article-727769.pdf

2. LABORATORY, H. A. (2000). REVIEW OF HAZARD IDENTIFICATION. Retrieved March 26, 2015 , from HEALTH AND SAFETY LABORATORY:http://www.hse.gov.uk/research/hsl_pdf/2005/hsl0558.pdf

3. Planning, N. G. (2008, July). Hazardous Industry Planning.Retrieved March 26, 2015, from http://www.planning.nsw.gov.au/plansforaction/pdf/hazards/haz_hipap8_rev2008.pdf