Hazop & Hazan: Identifying and Assessing Process Industry Hazards, Fouth Edition

by Kletz; Trevor A.

• ISBN13: 9781560328582
• ISBN10: 1560328584
• Edition: 4th
• Format: Hardcover
• Copyright: 1999-09-01
• Publisher: CRC Press

Summary

This revised edition provides the basics of applying hazard and operability study (Hazop) and hazard analysis (Hazan). Hazop is a creative but systematic method of identifying hazards in process plants. Hazard analysis is then used to quantify the risks from these hazards, and to assess how far to go in reducing them. This book is presented in easy-to-read style and explains: what a Hazop is, who carries it out, when, and how long it should take; points to watch during a Hazop; an example of a Hazop; Hazops on flowsheets; the stages of Hazard analysis; the Fatal Accident Rate; risks to the public; estimating how often an accident will occur, with examples; and pitfalls in Hazan.

Table of Contents

Preface	iii	(8)
Forethoughts	xi
1 Hazard identification and assessment	1	(8)
1.1 Introduction	1	(4)
1.2 A note on nomenclature	5	(2)
1.3 Legal requirements	7	(2)
2 Hazard and operability studies (Hazop)	9	(68)
2.1 What is a Hazop?	9	(11)
2.2 Who carries out a Hazop, and what should be recorded?	20	(6)
2.3 When is a Hazop carried out and how long does it take?	26	(1)
2.4 Some points to watch during Hazop	27	(7)
2.5 An example of a Hazop	34	(3)
2.6 Could a computer carry out a Hazop?	37	(4)
2.7 The limitations of Hazop	41	(6)
2.8 `Do we need to Hazop this plant?' `It is only a simple project' or `It is similar to the last one'	47	(3)
2.9 The use of quantitative methods during Hazop	50	(1)
2.10 The use of Hazop in other industries	51	(3)
2.11 Other methods of identification	54	(2)
2.12 Auditing Hazop	56	(1)
2.13 Conclusion	56	(5)
Appendix to Chapter 2 -- Some accidents that could have been prevented by Hazops	61	(16)
A2.1 Reverse flow	61	(1)
A2.2 Bhopal	62	(1)
A2.3 A fire in a water sump	63	(1)
A2.4 A protective device that did not work	63	(1)
A2.5 Services and modifications -- two neglected areas	64	(1)
A2.6 A computer-controlled batch reaction	65	(2)
A2.7 Abbeystead -- an explosion in a water pumping station	67	(1)
A2.8 The Sellafield leak	67	(4)
A2.9 Formation of separate layers	71	(1)
A2.10 The need for different sorts of knowledge	72	(3)
A2.11 An incident from another industry	75	(2)
3 Hazard analysis (Hazan)	77	(75)
3.1 Objective	77	(1)
3.2 Why do we want to apply numerical methods to safety problems?	78	(2)
3.3 The stages of Hazan	80	(3)
3.4 Choosing targets or criteria	83	(22)
3.5 Estimating how often an incident will occur	105	(15)
3.6 Pitfalls in Hazan	120	(10)
3.7 The man or woman in the middle	130	(3)
3.8 Examples of Hazan	133	(10)
3.9 A summary of the main sources of error in Hazan	143	(1)
3.10 A final note	143	(5)
Appendix to Chapter 3 -- Belt and braces	148	(4)
4 A manager's guide to hazard analysis	152	(16)
4.1 Introduction	152	(1)
4.2 Arithmetic, algebra and units	153	(1)
4.3 The model	154	(4)
4.4 The unforeseen hazards	158	(1)
4.5 The assumptions	159	(1)
4.6 Data	160	(2)
4.7 Human reliability	162	(1)
4.8 The recommendations	163	(1)
4.9 Comparison with experience	164	(1)
4.10 Closed shop or open shop?	165	(3)
5 Objections to Hazop and Hazan	168	(27)
5.1 Objections to Hazop	168	(1)
5.2 Technical objections to Hazan	169	(12)
5.3 Popular objections to Hazan	181	(6)
5.4 The regulator's view	187	(6)
Appendix to Chapter 5 -- Limitations on the application of quantitative methods to railway travel	193	(2)
6 Sources of data and confidence limits	195	(8)
6.1 Data banks and data books	195	(1)
6.2 If failure has never occurred	196	(1)
6.3 Confidence limits	196	(1)
6.4 Data on mechanical equipment may be data on people	197	(1)
6.5 Chaos	198	(1)
6.6 Pitfalls in extrapolating data	199	(4)
7 The history of Hazop and Hazan	203	(10)
7.1 Hazop	203	(4)
7.2 Hazan	207	(6)
Conclusions	213	(1)
Addendum 1 -- An atlas of safety thinking	214	(4)
Addendum 2 -- Myths of Hazop and Hazan	218	(6)
Index	224