HAZOP Pit Falls

8/16/2019 HAZOP Pit Falls

1/21

Introduction to Hazardous

Evaluation Techniques

• Guidelines for Hazardous Evaluation

Procedures (1992 by AIChE)• !econd Edition "ith #or$ed E%a&'les

• Center for Che&ical Process !afety(CCP!)

• A&erican Institute of Che&icalEnineers (AIChE)


2/21

Hazard Evaluation echni*ues

19+, - 2,,1 19+, - 2,,1 19+. - 2,,1 19/, - 2,,1 19/2 - 19/0 19/0 - 2,,1

Safety Check Lists Relative PHA What if HAZOP

Review Ranking

Walk Historical ICI Mond Preliinary !rainstoring Ha"ards#hro$gh Lists Inde% Ha"ard O&era'ility

Ins&ection Analysis Analysis

(es ) *o +ow ,-I

Ha"ardo$s Mtls Line 'y Line

Ha"ardo$s O&ns +eviation

Analysis

#his &resentation only considers the HAZOP techni.$e/


3/21

HAP

• HAP "as develo'ed by 3a"ley (19/0) ofICI 4ased on early account by Elliott 5 "en

(19+6)

• Hazo' studies are carried out by an

e%'erienced7 &ultidisci'lanary tea&

• 8evie" all 'hysical as'ects of a 'rocess

(lines7 e*ui'&ent7 instru&entation) to

discover 'otential hazards


4/21

Basis for HAP

• he basis for a HAP is a critical

e%a&ination of infor&ation found in a

"ord &odel• It includes a flo"sheet7 a 'lant layout7

e*ui'&ent s'ecification or a P5I7

(Pi'in and Instru&ent ra"in)


5/21

Hazo' Includes

1 Intention2 9eviation

: Causes

0 Conse*uences

(a) hazards

(b) o'eratin difficulties. !afeuards

+ 8eco&&endations ; Actions


6/21

Hazo' Guide #ords

*O or *O# *egation of intention *o ,low of A

MOR- 0$antitative increase ,low of A greater than design flow

L-SS 0$antitative decrease ,low of A less than design flow

AS W-LL AS 0$antitative increase #ransfer of soe co&onent additional to A

PAR# O, 0$antitative decrease ,ail$re to transfer all co&onents of A

R-1-RS- Logical o&&osite of intention ,low of A in direction o&&osite to design direction

O#H-R #HA* Co&lete s$'stit$tion #ransfer of soe aterial other than A

More recent co&$teri"ation techni.$es $se a Standard Set Of 2eneric +eviations

,or S&ecific Section #y&es/ See +ev3ns ta' for e%a&les/


7/21

Co&&on HAP Analysis

Process Para&eters,low #ie ,re.$ency Mi%ing

Press$re Co&osition 1iscosity Addition

#e&erat$re &H 1oltage Se&aration

Level S&eed #o%icity Reaction


8/21

Pre'are for the 8evie"

Attitude

Pre'aration no"lede Info for study

E%'erience ea&s HAP P5Ids7 3ayout

E%'erience

able

eviation Causes Conse*uences !afeuards Action


9/21

Hazop

Flow

Sheet

!elect a 'rocess

section or

o'eratin ste'

E%'lain desin 8e'eat for all

intention 'rocess sections

!elect a 'rocess 8e'eat for all

variable or tas$ 'rocess variables

A''ly uide "ord 8e'eat for all

to 'rocess variable uide "ords

E%a&ine evelo' action

Conse*uences ite&s

associated "ith

deviation

3ist 'ossible Assess acce'tability

causes of of ris$ based on

deviation conse*uences

Identify e%istin

safeuards to

'revent deviation


10/21

Hazop Pitfalls

Poor $nderstanding 'y anageent of the HAZOP &roced$re

An Ethylene 'lant has 1,, P5Is7 +2. e*ui'?t ite&s 456 ite&s

Consider . variables7 Pressure7 e&'erature7 =lo"

Co&'osition and =unction 6 variables

Consider + Guide"ords7 @one7


11/21

ther Pitfalls

• Ine%'erienced HAP tea&

• Inade*uately trained or in-e%'erienced

leader


12/21

Co&&on Hazo'


13/21

Hazo'


14/21

Hazo'


15/21

HAP E%a&'le

)o Co&'ressor Inlet

)ea&s tend to *uic$ly identify alar&s7 shut-do"ns

and controls7 and clai& the& for safe(uards

An alar& not tested &ay not "or$ "hen called u'on

Inlet 3ine to do so

@uisance alar&s are fre*uently by'assed and are

not effective as safe(uards

ften o'erators are not &onitorin( control 'anel

Ealve in &anual Auto&atic control routines are often set in &anual

&ode

=

1

3AH

3IC

1


16/21

!tandard !et of eviations

I @o eviation Colu&n essel 3ine E%chaner Pu&' Co&'ressor

1 Hih =lo" 8

2 Hih 3evel 8 8

: Hih Interface 8

0 Hih Pressure 8 8 8 8

. Hih e&'erature 8 8 8 8

+ Hih Concentration 8 8 8

/ 3o" ; @o =lo" 8 86 3o" 3evel 8 8

9 3o" Interface 8

1, 3o" Pressure 8 8 8 8

11 3o" e&'erature 8 8 8 8

12 3o" Concentration 8 8 8

1: 8everse ;


17/21

y'ical Hazo' #or$sheetCo&'any @ova 8evision 7 ate ,2-Fun-9/

3ocation Corunna " @o Cor -12:-0.+/ Pae 9

3eader RAH Proc es :! 8esearch ' ech

!cribe 2,R Instr?ts 2H Electrical HH ther Prod?n PM


18/21

Chec$ 3ist E%a&'le

1 Chanes In uantity a Hih =lo" 1 Pu&' racin7 delivery vessel 'ressure lost7

suction 'ressurized7 scale disloded7 lea$ in

heat e%chaner

3oss of auto&atic

control

b 3o" =lo" 2 Pu&' failure7 scalin of delivery7 'resence of

forein body7 'oor suction condition7

cavitation7 lea$ in heat e%chaner7 drain

lea$7 valve a&&ed

'erator error

c @o =lo" : Pu&' failure7 delivery vessel

over'ressurized7 as bloc$ae7 'resence of

forein body7 scale7 sedi&ent7 suction vessel

e&'ty

=ailure of oint7 'i'e7

valve7 tra'7 burstin

disc7 relief valve

d 8everse =lo" 0 Pu&' failure7 'u&' reversed7 delivery vessel

over 'ressurized7 'oor isolation7 as loc$in7

surin7 bac$ si'honin


19/21

Chec$ 3ist ContDd

2 Chanes in 'hysical

condition

a Hih or 3o"

'ressure

1 4oilin7 cavitation7 freezin7 che&ical

brea$do"n7 flashin7 condensation7

sedi&entation7 scalin7 foa&in7 as

release7 'ri&in7 e%'lodin7 i&'lodin

Chanes in viscosity7 density E%ternal =ire7

#eather conditions7 Ha&&erb Hih or 3o"

e&'erature

2 sa&e as 1


20/21

Chec$ 3ist ContDd: Chan(es in che&ical

condition

a Hi(h or 3o"

Conentration

1 Chan(es in 'ro'ortion of &i%ture7 in "ater or

solvent content

b Conta&inants 2 In(ress of air7 "ater7 stea&7 fuel7 lubricant7

corrosion 'roducts7 other 'rocess &aterials

fro& hi(h 'ressure syste&7 lea$a(e throu(h

heat e%chan(ers (as entrain&ent7 s'ray7

&ist

0 !tartu' and

!hutdo"n Condition

a )estin( 1 Eacuu&7 'ressure testin( "ith "ith har&less

&aterial

b Co&&issionin( 2 Concentration of reactants7 inter&ediates

c


21/21

End of HAP Presentation

• Presented to E!-:1/y

• 2/ =eb7 2,,1

• 4y 8A Ha"rela$

HAZOP Pit Falls

Documents