Understanding HAZOP_Rev.0.pdf

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A Passion for Safet y
Understanding
Hazard & Operability
(HAZOP) Study
Consultancy
Training
Testing
Offices in Europe, Asia and the Middle East
COURSE OBJECTIVES
On completion of the course you will learn:
 What is a PHA and HAZOP;
 Methodology and merits of HAZOP study
 Pre-requisites for HAZOP
 Conclusion of HAZOP.

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INTRODUCTION
SIGMA-HSE (INDIA) PVT. LTD.
AREAS OF EXPERTISE
 We bring together our Indian and UK experts to provide our clients
with EHS services and appropriate engineering solutions.
 We undertake Laboratory testing in our UK laboratories to ISO, BSI
ASTM and VDI individual test standards.
Consultancy Testing Training

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OUR PRESENCE
 Technical Offices
➢ New Delhi, India
➢ Mumbai, India
➢ Hyderabad, India
➢ Winchester, UK
➢ Abu Dhabi, UAE
 Laboratories
➢ Process Safety Lab, Winchester, UK
➢ The Environmental Laboratory (ELAB), UK
CONSULTANCY SERVICES
Our Consultancy team provides a wide range of specialist technical knowledge
covering the following sectors:
 Process Safety Management (PSM) Implementation
 Industrial Fire & Explosion Hazards
 Electrostatic Hazard Assessment
 Process Hazard Analysis (PHA)
 Functional Safety
 Chemical Reaction Hazards
 Training Workshops

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LABORATORY TESTING
 Powder Fire & Explosion Properties
 Gas and Vapor Properties
 Electrostatic Properties
 Chemical Reaction Hazard Testing
AGENDA
 PART I
➢ PHA – Basic Terminology
➢ PHA – Tools
➢ HAZOP Study
 PART II
➢ Preparatory Work
➢ HAZOP Study Procedure
➢ Roles & Responsibilities
➢ HAZOP Worksheet
 PART III
➢ HAZOP Workshop
➢ Useful Tips
➢ Advantages, Drawbacks &
Key Success Factors
 PART IV
➢ Mock HAZOP Study
➢ Q&A Session

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PART 1
TERMINOLOGY & BASICS OF
PHA & HAZOP STUDY
TERMINOLOGY
 Hazard
Potential source of harm. Deviations from design or operational intent may
constitute or produce a hazard. Hazards are the focus of HAZOP studies,
and it should be noted that a single hazard could potentially lead to
multiple forms of harm.
 Process Hazard
A type of hazard associated with deviation from process
parameter; e.g. High Level Leading to Overflow
 Non-process Hazard
A type of hazard, typically not associated with process parameters; e.g.
Fall from height, Vehicle impact onto piping leading to leak

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TERMINOLOGY
 Process Parameters
The characteristics of the process being evaluated; e.g. pressure,
temperature, level, flow etc.
 Design Intent
The intended action of unit operation within the process being evaluated;
e.g. for a heat exchanger, the design intent will be to heat the fluid to a
desired temperature
 Deviation
The variation of process parameter from required value i.e. design intent;
e.g. heat exchanger failing to heat the fluid to the desired temperature
TERMINOLOGY
 Process Risk
The risk associated with the process hazard and its consequences; e.g. for a
process hazard of high level leading to overflow, the process risk would be
the possibility of fatality due to pool fire
 Process Hazard Analysis
Structured & systematic identification of hazards associated deviation of
process parameters from design intent; e.g. identification of causes of high
level in a tank and the risk associated with consequences i.e. overflow &
pool fire
 Process Information

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PROCESS HAZARD ANALYSIS
 It is directed toward analyzing potential causes and consequences
of fires, explosions, releases of toxic or flammable chemicals and
major spills of hazardous chemicals, and it focuses on equipment,
instrumentation, utilities, human actions, and external factors that
might impact the process
 It is used to identify both process & non-process hazards
 Different tools being used for PHA are:
➢ HAZID
➢ HAZOP
➢ What-if
➢ Checklist
➢ Failure Mode Effects Analysis
HAZARD & OPERABILITY (HAZOP) STUDY
 A structured & systematic examination of a planned or existing
process or operation in order to identify and evaluate problems
that may represent risk to personnel or equipment or prevent
efficient operation
 Developed by ICI UK in the mid 1960’s
 A qualitative technique based on guide-words and is carried out by
a multi-disciplinary team during meeting/ set of meetings

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WHY TO DO HAZOP?
 It is an aid to design of safe plant
 It is a step in the overall procedure of safe plant design
 It is a training aid
 As an aid to design of operable plant
 For preparation of operating manual
 Systematic check of the safety and operability in the proposed
design
 To demonstrate the management, authorities and the public that all
possible efforts have been taken to avoid hazards
HAZOP – A TEAM ACTIVITY
A brain-storming activity where brains from different expertise are
brought together in collaborative efforts to:
 To ensure that all possible causes leading to hazards are identified
 To ensure that all possible consequence associated with identified
causes are defined
 To ensure that the qualitative risk associated with defined
consequences is adequately derived
i.e. to maker the design ‘safer’ in all possible aspects

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WHEN TO CONDUCT HAZOP?
 During FEED
 Detailed Design (at 30%,
70% and 100%)
 During any design change
 During pre-commissioning
 During normal operation
 For a audit requirement
/periodic study
17 A Passion for Safet y
PART 2
HAZOP STUDY

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OBJECTIVES
 Identification of potential causes of the harm
 Identify the potential deviations from the design intent and
operability issues
 Identification of further preventive/ mitigative actions where
risk associated is higher or safeguards are not available
 Identification of areas which would need more detailed
analysis than HAZOP
HAZOP – PREREQUISITES
 Process Flow Diagrams
 Piping & Instrumentation Diagrams
 Layouts & Plot Plan
 Material Safety Datasheets
 Process Description
 Operation Sequence Details
 Heat & Material Balance
 Equipment Datasheets
 Start-up & Emergency Procedures
 Cause & Effect Diagram

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HAZOP STUDY
Preparatory Work
HAZOP Workshop
Post-HAZOP Activities
HAZOP – PREPARATORY WORK
Review of
Process
Information
Node
Definition &
Mark-up
Terms of
Reference for
HAZOP Study

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NODE DEFINITION & MARK-UP
 What is Node?
 Is it a system based?
E.g. unit specific, equipment wise
 Is it a process based?
E.g. similar physical properties
of fluid, with same pressure,
temperature
What is preferred then?
NODE DEFINITION & MARK-UP

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HAZOP – TERMINOLOGY
 Risk Ranking
It is the process of
qualitatively determining
the risk as a combination
of severity and likelihood
with the help of standard
risk matrix.
Risk Ranking shall be
done considering the
consequences
HAZOP – DEVIATIONS
Deviation =
Parameter +
Guideword
DEVIATION PARAMETER GUIDEWORD
More Flow
Less/ No Flow
Misdirected Flow
Reverse Flow
High Pressure
Low Pressure
High Temperature
Low Temperature
High Level
Low Level
More
Less/ No
Other Than
Other Than
High
Low
High
Low
High
Low
Flow
Flow
Flow
Flow
Pressure
Pressure
Temperature
Temperature
Level
Level
DEVIATION PARAMETER GUIDEWORD
ChangedComposition
Failure of Utility
Sampling Issues
Failure of DCS
Start-up/Shutdown
Loss of Containment
Corrosion/ Erosion
Improper Maintenance
Engineering Issues/
Drawing Error
Other Than
Composition
Utility
Sampling
ControlSystem
Start-up/Shutdown
Leakage
Corrosion
Maintenance
Other issues

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SAFEGUARD TYPES
 Safeguards which detect deviation
e.g. detector, alarm, human operator detection
 Safeguards compensating for the deviation
e.g. automatic control system that stops the flow to tank on high level
 Safeguards preventing deviation from occurring
e.g. inert gas blanket in storage tank storing volatile liquid
 Safeguards preventing further escalation
e.g. automatic unit shutdown
 Safeguards relieving the process from hazardous deviation
e.g. pressure relief/ safety valves, vents etc.
SAFEGUARD TYPES (CONTD..)
Process Plant
Process
Control
Process
Alarms
Safety
Instrumented
Systems
Mechanical
Protective
Systems
Incident &
Emergency
Management
Procedures

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HAZOP – TEAM COMPOSITION
 HAZOP Chairman/ Facilitator/ Mediator/ Leader
 HAZOP Scribe/ Secretary
 Process Engineer
 Project Engineer
 Operations Expert
 Instrument/ Electrical Engineer
 Safety Engineer
 Maintenance Rep.
 Logistics Rep.
 Commissioning Engineer
 Vendor Package Specialist
Permanent Members
Additional Expertise
ROLES & RESPONSIBILITIES
 HAZOP Chairman
➢ Define the scope for the analysis
➢ Node definition
➢ Chair HAZOP session (trigger discussion using guidewords, moderate the
discussion around node being discussed, ensure completeness of
analysis, maintaining progress of session per schedule defined)
➢ Suggest/ drive discussions towards relevant conclusion and generation of
practical recommendations
 The Chairman shall be independent
➢ What is meant by independent chairman?

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ROLES & RESPONSIBILITIES
 HAZOP Secretary
➢ Supporting Chairman for Node definition & Mark-up
➢ Record proceedings of the workshop in the form of HAZOP worksheet
➢ Preparation of draft report under guidance of Chairman
 HAZOP Participants
➢ Process Engineer – process information
➢ Operations Expert – operations philosophy & methods
➢ Project Engineer – project details & procedures
➢ Other Members – provide input on matter of their expertise
HAZOP – PROCEDURE

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PART 3
HAZOP WORKSHOP
HAZOP WORKSHOP
MODES OF OPERATION
 Normal operation
 Reduced throughput operation
 Routine start-up
 Routine shutdown
 Emergency shutdown
 Commissioning
 Special operations
 Non-availability of utilities
Different modes of
operations shall be
considered for each node

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HAZOP WORKSHEET
Project: Node No.: N01
Design Intent: To separate R32 and HCl from feed as top stream in T-35211
Equipment Tags: T-35211, V-35201, P-35201A/B
P& ID No.: P&ID Revision No.: 0
HAZOP Worksheet Revision No.: Rev 0
Guideword
Paramete
r
Cause Consequence
Risk Ranking
Effective Safeguards Recommendations
Residual
Risk Ranking
S L RR S L RR
More Flow
1. More flow
from upstream
(feed)
1.1. Carryover of HF with
top product to HCl
absorption system leading
to contamination and HCl
loss. Environmental hazard.
4 4 16
1.1.1. FT in C2/HF feed line to
reactor with High flow alarm and
ratio calculator alarm.
1.1.2. FT-3520141 in line from V-
35201 to T-35211
1.1.3. FT-3520131 in column top
economiser outlet
1.1.1.1. High flow and ratio
calculator alarm in C2/HF feed
line to be taken on critical alarm
panel.
1.1.1.2. FT to be provided in
vapor line from V-35201 to T-
35211 in order to analyse any
upstream upset (such as utility
upset).
4 2 8
2. LV-3520121
stuck open/LT-
3520121
malfunctions
(vessel bottom)
2.1. Possible dry running of
P-35201A/B leading to
pump damage (No impact
on column due to limited
liquid inventory in V-
35201).
4 4 16
2.1.1. Valve position indication in
DCS
2.1.2. FT-3520141
2.1.3. DRP provided to P-
35201A/B
2.1.4. LG-3520121
2.1.1.1. Provide low level switch
on V-35201 with interlock to cut
off P-35201A/B.
4 2 8
AFTER THE WORKSHOP
HAZOP
Report
Preparation
Action
Tracking
Register
HAZOP
Close-out
Report

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HAZOP REPORT
TYPICAL CONTENTS OF HAZOP REPORT
 Introduction
 Process & facility description
 Process information referred/ analyzed
 Methodology
 Team composition
 HAZOP Recommendations
 Appendices
➢ HAZOP worksheet
➢ Node marked P&IDs
KEY SUCCESS FACTORS
 Accuracy of drawings and data used for the study
 Experience and skills of HAZOP chairman
 Technical skills & insights of the team
 Duration available for preparation of HAZOP workshop
 Schedule of workshop
 Ability of the team to use the HAZOP approach as an aid to
identify deviations, causes & consequences
 Ability of the team to maintain a sense of proportion, especially
when assessing the severity of the potential consequences

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ADVANATGES OF HAZOP
 Systematic examination
 Multidisciplinary study
 Utilizes operational experience
 Covers safety & operability aspects
 Can be used for human factor analysis/ assessment
 Solutions are suggested for identified problems
 Considers operational procedures
 Proceedings are recorded and are always available for reference
& training purposes
BATCH & CONTINUOUS PROCESS
ASPECT BATCH PROCESS CONTINUOUS PROCESS
Parameter Quantity of addition Flow of addition
Likelihood of
contamination
High, as the process equipment can
be used for multiple reactions/
operations
Lower, as the process equipment are
used for dedicated unit operations
Inventory Batches are generally smaller in
volume and thus the limited static
inventory
Continuous processes handle larger
inventory (static + dynamic)
Automation Rarely used; difficult to implement Commonly used; easy to configure
and implement
Setpoints A particular vessel may have different
set-points at different stages of
reaction
Set-points remain constant
Dependence on
operator
Higher dependence and hence
greater chances of human error
Lesser dependence and lesser
chances of human error

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PART 4
MOCK HAZOP DISCUSSION
NODE 1 (SOLVENT BULK STORAGE TANK)
42
Properties of Chemical
 Flammable
 Flash point: 4 c (closed cup)
 Auto ignition temp: 480 c
 TOXIC
 Boiling point: 110 c
 Melting point -95 c
 Vapour press. : 3.8 Kpa (25c)
 Reactive with oxidizing agents

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THANK YOU!
For Queries, contact our Process Safety Expert on +91 9599 024327 or
write to him on svarma@sigma-hse.com/ hchichra@sigma-hse.com
CONSULTANCY
▪ Hazard and Operability (HAZOP)
▪ Quantitative Risk Assessment (QRA)
▪ Safety Integrity Level (SIL) & Layer of
Protection Analysis (LOPA)
▪ Dust Explosion Risk Assessment
▪ Electrostatic Hazard Assessment
And OTHERS
PROCESS SAFETY TESTING
▪ Powder Fire & Explosion Properties
▪ Gas and Vapor Properties
▪ Electrostatic Properties
▪ Chemical Reaction Hazard Testing
DETAILED TRAININGS

Understanding HAZOP_Rev.0.pdf

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