18. chapter - 18 safety in chemical industry

8/19/2019 18. CHAPTER - 18 Safety in Chemical Industry

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CHAPTER - 18

Safety in Chemical Industry

1. Inevitable Place of Chemical Industry2. Need of Safety in Chemical Industry3. Types of Chemical Industry4. Statutory Provisions. Indian Standards!. Types of Chemical "a#ards and Controls$. %aterial &Property' "a#ards and

Controls$.1 Identi(cation of Chemicals$.2 %aterial Safety )ata Sheet &%S)S'$.3 Interpretation and use of %S)S$.4 Safety Precautions* Supervision and

%edical e+aminations$. Information to ,or-ers and thers$.! "a#ard Communication System

includin/ Safety and 0is- phrases. Stora/e "a#ards and Controls

.1 %aterial of Construction inin/.2 Stora/e essels their Safety

aspects.3 Pressure essels their Safety

aspects.4 0eaction or Process essels. 5lare.! Testin/* Types and Certi(cates.$ Corrosion* 6rosion* Causes*

Inspection and Prevention7. Process "a#ards and Controls 8

7.1 Types of Processes and perationsincludin/ 9nit Processes* 9nitperations other Processes

7.2 perational )eviations7.3 9se of essels* 6:uipments and

Control 0oom7.4 Safety in aboratory7. Speci(c Safety %easures for certain

Chemical Industries7.! 9se of Personal Protective

6:uipment1;. 9tility "a#ards and Controls11. Pollution "a#ards and Controls12. Instrumentation for Safe Plant

perations12.1 ects %odels14.3 %onitorin/ Control of

"a#ardous 6+posures1. n?Site and >?Site 6mer/ency Plans1!. Transportin/* 0eceivin/* Storin/ and

"andlin/ "a#ards and Control1!.1 Transportation and "andlin/ of

Chemicals1!.1.1 %odes of Pac-a/in/1!.1.2 %odes of Transport

?9N &)T@=)0' Classi(cation ? Transportation by 0ail* 0oad*

?,ater and Pipelines1!.2 "andlin/ of 5lammable Aases1!.3 "andlin/ of 5lammable i:uids1!.4 "andlin/ of 5lammable Solids1!. "andlin/ of +idisin/ =/ents1!.! "andlin/ of Corrosive

Substances1!.$ "andlin/ and Stora/e of

Chlorine1!. "andlin/ and Stora/e of

=mmonia1!.7 "andlin/ and Stora/e of PA1!.1;"andlin/ and Stora/e of 61!.11"andlin/ and Stora/e of leum1!.12"andlin/ of Aas Cylinders

1$. Inspection* Testin/ %aintenance1$.1 Process 5laB chart its

importance for Inspection1$.2 Inspection Techni:ues for

Plants* essels Procedures1$.3 Chec-list for 0outine

Inspection of a Chemical 5actory1$.4Start?up ShutdoBn Procedures1$. %aintenance

1. ,or- Permits for "a#ardous Bor-1.1 Aeneral Chec-?list1.2 Permit for essel 6ntry

17. 0eports of Some 6+pert Committees17.1 Aar/ Committees 0eport

&17'17.2 0eport of the AuDarat Tas-

5orce Committee &17'17.3 =n 6+tract of the Inspection by

three I 6+perts on Inspectionof 71

%=" 5actories.

1

THEME


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1 INEVITABE PACE !"CHE#ICA IN$%STR&

The safest and simplest Bay to avoidchemical ha#ards and their ill?e>ects is toavoid chemical industry itself.


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te+tiles' and employ 14!7 Bor-ers out of total $;$! i.e. 21.!4G in the State. Table.21 states that accidentBise also it is second&ne+t to te+tile' contributin/ 1;7; out of 12;31 i.e. .7G accidents. The percenta/eof fatal accidents in chemical factories Bas

3;.7G in 177$ in AuDarat.Indian statistics of 17$7 states that thereBere 74 &Total of NIC Aroup No. 3; 31'out 131$3 i.e. $.;1G chemical factories and!;7;;; out of !$7$;;; i.e. .7G Bor-ers inthese factories. =s the latest all Indiastatistics is not available* it is estimated thatthis percenta/e Bould have reached up to1;G. )urin/ 1772 there Bere 4141 out of !4!31 i.e. !.4;G accidents in chemicalfactories Bhich can also be estimated to riseup to G durin/ last ! years.

Thus it can be concluded that there areabout 10% chemical factories in India,

employing 10% of total manpower andcontributing @10% of total accidents.

In Guarat chemical factories are @!1%,employing @!1% of total manpower,contributing @"% of total accidents and@#1% of fatal accidents.


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Section 7!= for penalty for breach of section41


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HoB meters 711* venturi meters 44$$* (redetectors 217* 21$* (re e+tin/uishers 217;*7! &See Part 3 4.2 of Chapter?13 also'*/as industry $;!2* /as mas-s 23* /as oven$342* 44$3* /as pressure pipes 327* /asscrubber* cooler or absorber 724;* /ases

Hammable classi(cation 7$;* /as detection$$$* 1;3!* /aseous emissions ? nitric acid7;;* sulphuric acid !3* perchlorates of ammonium* potassium and sodium 13714*sulphur dio+ide 1371;* petroleum re(neries!3!* process control valves 1;1$* manholefor chemical e:uipment 3133* measurin/cylinders $* solid mineral fuels 31;*testin/ atmospheric conditions 17!* thermalinsulatin/ material $24;* $413* thermocouplepyrometers 2;3* vacuum?(lters !;34* !$!*/au/e 2$!* pump !47* technolo/y 411;*24* valve?ball 77; for PA cylinders $3$*$$!* /lobe steel 1;!;* Bor- environment

monitorin/ code 7!$7* safety inmicrobiolo/ical laboratories 12;3.

Auide for handlin/ cases of pesticidepoisonin/ 4;1 &Part 18 5irst?aid measures*Part 28 Symptoms* dia/nosis and treatment'*pac-in/ !!;4* code of safety for malathion1;$2* #inc phosphide 72$* aluminiumphosphide 72$7.

PA stora/e installations !;44 &Part 1 2'* code of safety in electric and /as Beldin/and cuttin/ operations 1.

9n(red pressure vessels 22* steelfor/in/ for (red and un(red pressure vessels

7!3* /lossary of terms relatin/ to corrosionof metals 331* cathodic protection of steelstructures ;!2 &Part 1 to 4'* safety incompressed air 413* steel plates forpressure vessels 2;41* Non?destructivetestin/ ? ma/netic particle 341* 3$;3* $$43*1;$24* 1;43* radio/raphy 24$* 27* 27*li:uid penetrants 127* concrete methods13311* ultrasonic testin/ 241$* 734!* 11!3;*eddy current 127!.

5ire safety of buildin/s 374* ventilationin petrochemical plants and re(neries 12332*classi(cation of Hammable /ases@vapoursBith air accordin/ to their ma+imum

e+perimental safe /aps and minimum i/nitin/currents 7$;* maintenance and operation of petroleum stora/e tan-s 77!4 &Part 1 2'*safety in electro?heat installations 7;; &Part1 to 4'* Hash bac- arrestor &Hame arrestor'11;;!* purchasers data sheet for /asscrubber* cooler or absorber 724;* safety beltand harnesses 321* breathin/ apparatus1;24 &Part 1 to 4'.

%ethods of samplin/ chemicals andchemical products 3 &Part 1 2'* methodsof samplin/ and test for industrial eJuents24 &Part 1 to '* tolerance limits for

industrial eJuents C") 12* or 247; &Part 1 to1;'* treatment and disposal of eJuents of cotton and synthetic te+tile industry 7;*

li:uid sedimentation methods fordetermination of particle si#e of poBders22* solid Baste analysis 1;1.

Plant layout* safe practice ;7* ;71*emer/ency shoBers and face mountains1;72* safety colours and si/ns 74$*

accident prevention ta/s ;7* /as detectortubes 13273.Code of Practice on ccupational Safety

and "ealth =udit 1447.

!IS$ Standards +

il Industry Safety )irectorate &IS)' haspublished the safety standards for oilre(neries* PA bottlin/ plants* /as terminals*NAC and A=I installations etc. Some suchstandards are mentioned beloB 8

!IS$ Standards +

IS)?1;! Process desi/n and operatin/philosophies on pressure relief and disposal system.

IS)?11; 0ecommended practices onstatic electricity.

IS)?112 Safe handlin/ of air?hydrocarbonmi+tures and pyrophoricsubstances.

IS)?11$ 5ire protection facilities forpetroleum depots andterminals.

IS)?11 ayouts for oil and /asinstallations.

IS)?117 Inspection of pumps.IS)?12; Inspection of compressors.IS)?121 Inspection of turbines diesel

en/ines.IS)?123 Inspection of rotatin/

e:uipment components.IS)?124 Predictive maintenance

practices.IS)?12 Inspection and maintenance of

mechanical seals.IS)?12! Speci(c maintenance practices

for rotatin/ e:uipment.IS)?12$ "istory recordin/ of rotatin/

e:uipment.

IS)?12 Inspection of un(red pressurevessels.

IS)?13; Inspection of pipes* valves and(ttin/s.

IS)?132 Inspection of pressure relievin/devices.

IS)?13$ Inspection of electricale:uipment.

IS)?14; Inspection of Detty pipelines.IS)?144ol. I

PA bottlin/ plant operations ?)esi/n philosophies.

ol. II peratin/ practicesol. III Inspection and maintenance

practices

ol. I Safety and (re protectionIS)?14! Preservation of idle electrical

e:uipment.

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IS)?14$ Inspection and safe practicesdurin/ electrical installations.

IS)?14 Inspection and safe practicesdurin/ overhaulin/ electricale:uipment.

IS)?13

%aintenance inspection of safety instrumentation in

hydrocarbon industry.IS)?14 Safety aspects in functional

trainin/.IS)?1! 5ire protection facilities for port

oil terminals.IS)?1!; Protection of (ttin/s mounted

on e+istin/ PA tan- truc-s.IS)?1!1 0escue and relief operation

involvin/ tan- truc- accidentcarryin/ PA.

IS)?1!2 Safety in installation andmaintenance of PA cylindermanifold.

IS)?1!7 Small PA bottlin/ plants

&)esi/n and (re protectionfacilities'.

See Chapters 11* 13* 24 and 2 forrelevant Indian Standards on the subDects of electricity* (re and e+plosion* industrialhy/iene and health and personal protectivee:uipment.

, T&PES !" CHE#ICAHAAR$S AN$ C!NTR!S

People Bor-in/ in chemical factories and

dBellin/ nearby are e+posed to various typesof chemical ha#ards. InHammable* e+plosive*to+ic* corrosive* reactive* radio active*o+idisin/* reducin/* decomposin/* compatibleand hidden ha#ardous nature of chemicalspose material or property ha#ards. In process*chemical and physical chan/e* chemicalreaction* pressure* temperature* level* HoB*:uantity and other parameters create processha#ards. The vessels and e:uipment in Bhichthe chemicals are stored* handled orprocessed* pose vessel ha#ards. Theinade:uate* defective* underdesi/ned or

Bron/ly modi(ed control devices or failurethereof cause control ha#ards. 5ire ore+plosion cause (re ha#ards. 6Juent disposaland /aseous emissions brin/ pollution andto+ic ha#ards. ea-s* spills and splashescause handlin/ ha#ards. =bsence* non?use orfailure of (re (/htin/ e:uipment* personalprotective e:uipment* emer/ency controldevices reveal accident and emer/encyha#ards. =ll other unsafe Bor-in/ conditionsand unsafe actions pose a variety of ha#ardsthat all need to be prevented and controlled.

%any safety measures are available todeal Bith above ha#ards. Identi(cation of contents* properties* ha#ards and :uantity of chemicals* their content minimisation* proper

storin/* handlin/ and pac-in/O auto control*recordin/ and Barnin/ devices for level*pressure* vacuum* temperature* HoB* feed*speed* coolin/* heatin/* stirrin/* dischar/e*contaminationO remote control devices* properventilatin/* e+haust* scrubbin/* neutralisin/*

inactivatin/ and incineratin/ devicesOmonitorin/* measurin/* recordin/* trippin/*correctin/ and controllin/ system* (re (/htin/and personal protective e:uipment*emer/ency and disaster plannin/* controlsand all en/ineerin/ Bell desi/ned process andplant layout and fully safe actions of Bor-?people are utmost necessary to (/ht theseha#ards and to control over them. The basicsteps in short are as folloBs 8

1 Identi.cati/n /f Health 0T/ic2Ha3ards +

$a Types of e&ects are '=ller/y* Irritation* +y/en de(ciency

&asphy+iation'* Systemic poisonin/ &e/dama/e to liver* -idney* CNS* reproductivesystem etc.'* Cancer* )ama/e to unbornefoetus&terato/enesis'* Aenetic e>ects onfuture /enerations &muta/enesis'* )ust e>ect&pneumoniosis'.

Some e>ects are acute &local or shortterm' and some are chronic &lon/ term*delayed or after repeated e+posures'.

$b (actors creating e&ects are '

Type of concentration of chemical*Combined e>ects of mi+tures* Properties of the material includin/ its to+icity* ,or-methods* Nature of e+posure &short term*lon/ term' 0outes of entry &throu/h nose*mouth or s-in' and Individual susceptibility.

' Identi.cati/n /f /ther ha3ards +

$a (ire and )*plosion +aards -"eat /eneration due to chemical

reaction* pen Hame* 0adiant heat* 5ricton*Spontaneous combustion* 6lectric current*Static electricity etc.

$b (uel or olvents 'oB Hashpoint and oB boilin/ point

li:uids* Aases and Solids &dusts* poBders*lumps* crystals'

$c /tomic adiation '0adioactive substances and 0adiation

processes &?ray* N)T* Nuclear poBer plantetc.'

(4 Pre5enti5e 6 C/ntr/l #easures +

$a i* asic 2rinciples '

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• 6limination of substance or process.

• Substitution of safer alternative.

• )istance* Auard* 6nclosure* Isolation*Shieldin/ or Se/re/ation of ha#ardousprocess.

• entilation* /eneral local e+haust.

• Personal Protective 6:uipment.• Personal hy/iene.

$b 3anagement 4ontrol 'Identi(cation* %S)S* abellin/* Safestora/e* Safe Transfer procedure* Safehandlin/ use* Safe processes operations* Safe disposal methods* Aoodhouse-eepin/* %easurement assessment &%onitorin/'* %edicale+amination* record and treatment&medical surveillance'* 0ecord?-eepin/ of Bor- e+posure monitorin/* environmental

or air :uality monitorin/* medical andbiolo/ical monitorin/* Trainin/ education to Bor-ers and Supervisionincludin/ safety Bor- permits and safeBor- methods.

)4 Emer7ency C/ntr/l Pr/cedures +

• Speedy ea- Spill Control procedures.

• 6mer/ency shut?doBn procedure.

• n site emer/ency plan.

• > site emer/ency plan.

• %utual aid arran/ement Bith

nei/hbourin/ industries.• 0etainership for help at the time of

emer/ency.• 0e/ular rehearsal of emer/ency

procedures &drill'* updatin/ and revieBin/of the plan.

#ATERIA 0PR!PERT&2HAAR$S AN$ C!NTR!

%a-e a list of all raB materials* products* by?products and intermediates. Identify them by

their nature of ha#ard and ris- potentials.Classify them as inHammable* e+plosive*to+ic* corrosive* radioactive* reactive*o+idisin/* irritant* unstable* compressed/ases* dust and others. =lso note theirha#ardous properties vi#. boilin/ point* Hashpoint* 6* 96* )* C* T* %=C* I)"*density* solubility etc.* to understand the ill?e>ects of the chemical. 0eference No. 1 to 4/iven at the end of this chapter e+plain allsuch terms and /ive them for variouschemicals. 0eference No. 11 /ives suchha#ardous properties of some selectedchemicals.

The chemicals may cause either physicalha#ards or health ha#ards. The physical

ha#ards are caused due to dust* corrosive*e+plosive* Hammable and reactive chemicals*compressed /ases and o+idisers. The healthha#ards are caused due to to+ic* irritant andcarcino/enic chemicals. Carcino/enic causescancer. %uta/enic causes inherited chan/es

and terato/enic causes harm to unborn.%icro?or/anisms and radioactive chemicalsalso cause health ha#ards. The ha#ards arealso classi(ed as (rst and second de/reeha#ards. The (rst de/ree ha#ards are causedby corrosive* Hammable* e+plosive* to+ic ando+idisin/ chemicals* heat or i/nition source*human error and failure of e:uipment etc. Thesecond de/ree ha#ards inDure life andproperty and include (re* e+plosion* to+ice+posure* corrosive chemicals* collision*slippin/* fallin/ etc.

41 Identi.cati/n /f Chemicals

Identi(cation of chemicals be/ins Bith the-noBled/e of basic chemistry. 0efer Table No.1 in Chapter 32 to identify (rst somecommonly used elements and radicals. ThisBill help to identify the chemicals.

Chemicals are classi(ed in di>erent Bays.5or study &chemistry' point of vieB* they arebroadly classi(ed as inor/anic and or/anicchemicals. Inor/anic chemicals aresubclassi(ed as metals and non?metals. utof 1;4 elements* ; are metals and maDorityof them &e+cept mercury' are solids* shinin/*

reHectin/* /ood conductor and formin/reducin/ a/ents and basic hydro+ides. In non?metals* more than half are /ases andremainin/ are hard solid* non?shinin/* lessreHective* bad conductor and formin/o+idisin/ a/ent and acidic hydro+ides. Somee+amples are /iven beloB 8

#etals + =luminium* =rsenic*


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=romatic alcohol* =romatic aldehydes*Metones and :uinones and =romaticcarbo+ylic acids.

Heter/cyclic C/m9/unds and P/lymers&Bith other?rin/s' + 5uran* Pyrrole* Thiophene*

Pyridine* uinoline* Iso:uinoline* =l-aloids?coniine* nicotine* )ru/s* "ormones* itamins*6n#ymes and Polymers ? Natural andSynthetic 0ubber li-e neoprene* butadieneOsynthetic (bres li-e nylon* orlon* vinyon*terylene* Synthetic plastics and resins li-ecellulose* formaldehyde* al-yd* vinyl* acrylateand polystyrene resins and silicones.

Chemicals are also classi(ed as under 8

1. Acc/rdin7 t/ their Physical State i.e.solid* li:uid or /ases. 5ine particles of solidli-e poBder* dust* fumes and smo-e are

called particulate matter. Their suspensionin air or /as also e+ists. i:uids areclassi(ed as acid* al-ali* solvent*suspension* li:uid mi+ture* aerosols etc.Aases are classi(ed as inert &N2* C2'*reactive* to+ic* irritant* corrosive etc.

2. N/i/us :ases 8• Irritant /ases ? Cl2* N"3* S2* N2*

CC2* =ldehydes etc.• Systemic poisons ? C!"!* CS2* P"3*

Stibine* %n* Nic-el carbonyl* =rsine*"alo/enated hydrocarbons etc.

• Simple asphy+iates ? N2* C"4* C2 etc.

• Chemical asphy+iates ? C* "2S* "CNetc.

(4 $ust 0Particulate #atter2 +• Causin/ plenumoconioses ? Coal* Silica*

=sbestos etc.• Causin/ =sthma ? Cotton* 5lour* T)I etc.

• Causin/ aller/y ? fun/al spores* birdfanciers* lun/* ba/assation etc.

• Causin/ lun/ cancer ? Chromium*=sbestos*


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)initrochloroben#ol* Cyanide of potassiumand sodium* Cyano/en /as* Cyclohe+ane*)initrophenol* 6thyldichloroarsine* "e+aethyltetraphosphate* "ydrocyanic acid and itsfumes* %ercuric acetate* %arcuric ammoniumchloride and ben#oate* %ercuric cyanide*

bromide* o+ide* Iodide* %ethyl bromide*%ethyl dichloroarsine* %ustard /as* Nic-elcyanide* Nitroben#ol* Nitro/en pero+ide*Phos/ene* Thio phos/ene* Qinc arsenate* %IC&methyl iso?cyanate'* Carbon mono+ide*Cadmium* ))T* %ethanol* Phosphine anddan/erous pesticides such as Parathion*)ia#eomon* Tetraethyl pyrophosphate*

Tetraethyl phosphate* )emeton* Scheadan*%ethyl parathion* Cryolite* Pentachlorophenol.)initro?o?cresol* 6ndrin etc.Pesticides - Insecticides +

2esticides 8 =luminium phosphide* aldrin*acephate* antu*


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nitrous* sulphurous* sulphonic*chlorosulphonic* boracic or boric* phosphoric*phosphorous* perchloric* arachidic* arsenic*ascorbic* aspartic* aspirin* hydra#oic* behenicor docosanoic* bromic* chloric* chloroplatinic*chlorous* chromic* iodic* man/anic*

metaphosphoric* perboric* perman/anate*persulphuric etc.6rganic 8 =cetic* acrylic* adipic* amino or

carbo+ylic* al/inic* uric* uncleic* succinic*barbituric* ben#enesulphonic* ben#oic* capricor decanoic* he+anoic* caprylic or octanoic*carbolic or phenol* carbonic* carbo+ylic* carosor persulphuric* ricinoleic* chloroacetic*cinnamic* citric* crotonic or butenoic* cyanic*cyanuric or tricyanic* ethylene diaminetetraacetic acid &6)T='* fumaric* /alic*/luconic* he+anoic* hydrodic* hydrobromic*hydrocyanic* hydroHuoric* hydro#y*hypoclorus* hypophosphorous* isophthalic*

lactic* lauric* linole/ic* meleic* malic* malonic*mandelic* methacrylic* molybdic* monobasic*necotinic* nucleic* octanoic* oleic* oleum*osmic* o+olic* o+ydiacetic* o+ydiethanoic*palmitic* pantothenic* pelar/onic* phosphinic*phthalic* picric* pyrophosphoric*pyrosulphuric* pyruvic* racemic* ribonucleic*ricinoleic salicylic* sebacic* selenic* silicic*stannic* stearic* suberic* sulphanilic* fannic*tartaric* thiocyanic* thiosulphuric* tribasic*trihydro+yben#oic* uric* vanadic etc.

5olloBin/ tBo tables are reproduced fromthe 0eference No. 13 /iven at the end of this

Chapter 8

Ta;le-1841+ Partial ist /f Inc/m9ati;le Chemicals0Reacti5e Ha3ards2

Substance in the left hand column should bestored and handled so that they cannotpossibly accidentally contact correspondin/substance in the ri/ht hand column underuncontrolled condition because violentreactions may occur.

=cetic acid Chromic acid* nitricacid* hydro+yl?containin/compound* ethylene*/lycol* perchloricacid* pero+ide andperman/anates.

=cetone Concentrated nitric sulphuric acidmi+tures

=cetylene Chlorine* bromine*copper* silver*Huorine

=l-ali and

al-aline earthmetals such as

Carbon dio+ide*

carbon tetrachlorideand other

sodium*potassium*lithium*ma/nesium*calcium*poBdered

aluminium

chlorinatedhydrocarbons &alsoprohibit Bater foamand dry chemical on(res involvin/ thesemetals. )ry sand

should be available'.=mmonia&anhyd.'

%ercury* chlorine*calcium hypochlorite*iodine* bromine andhydro/en Huoride

=mmoniumnitrate

=cids* metalpoBders* Hammableli:uids* chlorites*nitrites* sulphur*(nely dividedor/anics orcombustibles.

=niline Nitric acid* hydro/enpero+ide


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propane*/asoline*turpentine'"ydrocyanicacid

Nitric acid* al-alis

"ydroHuoric acid =mmonia

"ydro/enpero+ide

Copper* chromium*iron* most metals ortheir salts* anyinHammable li:uid*combustiblematerials* aniline*nitromethane

"ydro/ensulphide

5umin/ Nitric acid*o+idisin/ /ases

Iodine =cetylene* ammonia%ercury =cetylene* ammonia*

fulminic acidNitric acid

&Conc.'

=cetic acid* acetone*

alcohol* aniline*Chromic acid*"ydrocyanic acid*"ydro/en sulphide*Hammable /asesand nitratablesubstance

NitroparaFns Inor/anic bases*amines

+alic acid Silver* mercury+y/en ils* /rease*

hydro/en* Hammableli:uids* solids or/ases

Perchloric acid =cetic anhydride*bismuth and itsalloys* alcohol*paper* Bood* /rease*oils

Pero+ides*or/anic

=cids &or/anic ormineral'* avoidfriction* store cold

Phosphorous&Bhite'

=ir* o+y/en

Potassiumchlorate

=cids

Potassiumperchlorate

=cids

Potassiumperman/anate

Alycerol* 6thylene/lycol*ben#aldehyde*Sulphuric acid

Silver =cetylene* +alicacid* Tartaric acid*=mmoniumcompounds

Sodium nitrite =mmonium nitriteand other=mmonium salts

Sodium pero+ide =ny o+idisable

substance such asethanol* methanol*

/lacial acetic acid*=cetic anhydride*


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4. Trade name. Chemical Classi(cation!. 0e/ulated identi(cation$. Shippin/ Name* Codes@abel. C=S No.7. 9N No.

1;. =)0 No.11. "a#chem &6=C'No.12. "a#ardous ,aste I) No.13. "a#ardous In/redients and C=S No.

'4 Physical 6 Chemical $ata +

1. =ppearance* State* dour etc.2. Speci(c /ravity &,ater R 1'3. apour density &air R 1'4. ects of e+posure and symptoms7. 6mer/ency and (rst aid treatment

1;. 6n/ineerin/ controls necessary for safehandlin/.

11. N5P= "a#ard si/nals12. Special "ealth ha#ards.

,4 Pre5enti5e #easures +

1. entilation re:uired and type2. Personal protective e:uipment re:uired

and type3. "andlin/ and stora/e precautions

4 Emer7ency and "irst-aid #easure +

1. Steps to be ta-en in case material isreleased or spilled.

2. ,aste disposal method for solid* li:uidand /aseous Baste.

3. 5ire* e+tin/uishin/ media* specialprocedures and 9nusual ha#ards.

4. 6+posure ? 5irst?aid measures* =ntidotes*)osa/es.

84 Additi/nal Inf/rmati/n < References +

=4 #anufacturer < Su99lier>s $ata +

1. Name of 5irm2. %ailin/ address3. Telephone@Tele+@5a+ Nos.4. Tele/raphic address. Contact person in emer/ency!. ocal bodies involved

$. Standard pac-in/. Tremcard )etails @ 0ef.7. ther

1?4 $isclaimer +

4( Inter9retati/n and use /f#S$S

5or the better understandin/ and use of the%aterial Safety )ata Sheet* some terms aree+plained beloB 8

14 "/rmula 0Chemical2 + It is a symbolicrepresentation of a chemical entity orrelationship betBeen elements* molecule andatoms. e./. "2 one molecule of hydro/en*2"2S4 tBo molecules of sulphuric acid* "2one molecule of Bater Bherein there are tBoatoms of hydro/en and one atom of o+y/en.C!"! ben#ene contains si+ atoms of carbonsand si+ atoms of hydro/en in one molecule*/roup or ion. Thus by formula Be can -noBthe ha#ardous in/redient of a chemical.

'4 Syn/nym + Indicates alternate name of amaterial. e./. )imethyl -etone or 2?Propanonefor =cetone.

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(4 Trade Name + Commercial name of theproduct.

)4 Chemical Classi.cati/n + Aeneralclassi(cation is or/anic or inor/anic."a#ardBise classi(cation can be Hammable*

e+plosive* to+ic or poisonous* corrosive*reactive* infectious* o+idisin/* radioactive etc.

*4 CAS N/4 + It is Chemical =bstracts Servicenumber to provide a sin/le uni:ue identi(erBith namin/ the chemical. e./. C=S No. foracetic acid is !4?17?$. It does not indicate theha#ards of a material.

,4 %N N/4 + It is 9nited Nations four di/itnumber assi/ned to potentially ha#ardousmaterial &e./. =mmonia 9N No. 1;;' or Classof material &e./. corrosive li:uids 9N No.1$!;'.

These numbers are internationallyreco/nised and used by emer/ency responsepersonnel &includin/ ire (/hters' to identifymaterial durin/ transport emer/encies. 9N*"a#chem* N= and PIN numbers have thesame uses.

4 Ha3chem 0EAC2 N/4 + "a#chem&ha#ardous chemical' Code or 6=C&6mer/ency =ction Code' is an emer/encycode con(rmed by the "ealth Safety6+ecutive* 9M. It consists of a number &1 to 4'

folloBed by one or tBo letters and si/ni(estype of a (re e+tin/uisher re:uired* type of personal protective e:uipment re:uired*Bhether the spilla/e should be contained ordiluted Bith Bater* Bhether the material isreactive and Bhether evacuation of thesurroundin/ area necessary. "a#chem No. of Sodium cyanide is 4 and that of inylchloride is 2,6.

84 A$R N/4 + It is an =/reement concernin/carria/e of )an/erous /oods by 0oad. This6uropean a/reement Bas arrived at Aenevaby 17 6uropean countries for the safety of

international transport by road. It deals Biththe classi(cation of ha#ardous substances*their pac-a/in/* loadin/ and unloadin/*transportation and its e:uipment. It /ivesha#ard identi(cation numbers li-e 9N ha#ardclass number. Their comparison is /ivenbeloB.

Classi.cati/n /f $an7er/us ://ds ;y

78 8umber /9 8umber

1 6+plosives. 2 6mission of /as2 Aases?

Compressed*

due to pressure

orli:ue(ed* due to chemical

dissolvedunder pressure or reaction.deeplyrefri/erated.

3 5lammability of

3 5lammableli:uids.

li:uids&vapours'

4 5lammable solids. and /ases. +idisin/ 4 5lammability of substances or /ases.r/anicPero+ides.

+idisin/ &(re

! Poisonous &To+ic'or

intensifyin/'

Infectious e>ect.substances. ! To+icity.

$ 0adioactive Corrosivity.substances. 7 0is- of sponta?

Corrosive neous violentsubstances. reaction.

7 %iscellaneous

dan/eroussubstances.

)oublin/ &repeatin/' of an =)0 di/itindicates increase of that particular ha#ard.Pre(+ indicates that the substance candan/erously react Bith Bater. =s an e+ample=)0 "IN &Ha#ard Identi(cation No.' of


14/126

easy comparison of /ases. i/hter /ases&d1* e./. ammonia ;.7' Bill /o up &rise' inthe air and heavier /ases &d1* e./. chlorine2.47' Bill come doBn on the bottom. Thisinformation is useful for ventilation desi/nand evacuation &emer/ency' activity.

1'4 B/ilin7 P/int + It is that temperature atBhich the material chan/es from a li:uid to a/as.

enou/h vapour near its surface to form aHammable air vapour &/as' mi+ture so that itcan be i/nited if a spar- is available. TheloBer Hesh point indicates hi/her ha#ard as itcan cause (re at a loBer temperature. It ise+pressed as Closed Cup &CC' or pen Cup&C'. CC value is sli/htly less than the Cvalue.

'(4 Aut/i7niti/n Tem9erature + It is theloBest temperature at Bhich a materialbe/ins to burn in air Bithout any contact of spar- or Hame. )urin/ heatin/ if the material

decomposes* the decomposed chemical mayauto?i/nite at some other temperature.)i>erent test methods /ive di>erent auto?

14


15/126

i/nition temperatures for the same material. Therefore this value is an estimate. Thematerial should be stored* processed orhandled Bell beloB its auto?i/nitiontemperature to avoid the ris- of self (re ore+plosion.

Substances liable to spontaneouscombustion are those liable to spontaneousheatin/ under normal conditions or to heatin/up on contact Bith air and bein/ then liable tocatch (re.

')4 "lamma;le /r E9l/si5e imits0Eect of Hame* heat orphoto?chemical conditions or Bhich are moresensitive to shoc-s or friction thandinitroben#ene &old de(nition' or pyrotechnicsubstance &(reBor-' or Bhich is capable of producin/ /as at such temperature* pressureand speed to cause dama/e to surroundin/sor e+othermic reaction by heat* li/ht* sound*/as* smo-e or their combination &neB

de(nition'.

'84 C/m;usti;le and "lamma;le #aterial+ 5lammable solid* li:uid or /as Bhich cancatch (re and burn rapidly or e+plosively areHammable materials.

The terms combustible and Hammableboth indicates the ability of a material toburn. =ny material that Bill burn at anytemperature is combustible by de(nition.(lammable are a special /roup of combustiblematerials that i/nite easily and burn rapidly.5or e+ample* NaCl* CCl4 and C2 are non?combustible Bhile su/ar* cellulose and

ammonia are combustible but non?Hammable. The more readily i/nition occurs* the

more Hammable the material* less easilyi/nited materials are said to be combustible*but the line of demarcation is diFcult todecide.

Normally combustible li


16/126

5lammable ? havin/ Hash point betBeen !;;Cand 7;;C.

Thus li:uids havin/ Hash point betBeen3$.$;C to 7;;C can be called combustible asBell as Hammable* Bhile those havin/ Hashpoint /reater than 7;;C should be called

combustible.5lammable li:uids are e+tremelyha#ardous* as they /ive o> vapours at loBtemperature and these vapours by travellin/to a source of i/nition can cause Hash bac- tothe Hammable li:uid. It is diFcult toe+tin/uish a burnin/ Hammable li:uid BithBater because Bater may not be able to coolthe li:uid beloB its Hash point.

(lammable gases &normally boilin/ point 2; ;C' are e:ually ha#ardous as Hammablevapours as e+plained above. Con(nedHammable /ases are most dan/erous.5lammable /ases are also de(ned as those

Bhich at 2;;C and at standard pressure of 1;1.3 MPa* have 6 13G or less or aHammable ran/e of 12G or more re/ardlessof the 6.

(lammable solids can be i/nited due toe+ternal heat* Hame* process heatin/ byinteraction Bith Bater or other substances.5lammable solids are of various types &1')usts or (ne poBders e./. cellulose* Hour etc.&2' Spontaneously i/nitable at loBtemperature e./. yelloB phosphorous &3'

Those in Bhich internal heat is built?up bymicrobial or other de/radation activity e./.

(sh meal* Bet cellulosic material &4' 5ilms*(bres and fabrics of loB?i/nition pointmaterials.

5lammable solids are readily combustibleor may cause or contribute to (re throu/hfriction or Bhich are liable to under/o a stron/e+othermic reaction.

'=4 C/rr/si5e #aterial + It can attac-&corrode' metals or human tissues such ass-in or eyes. Structure or metal containermay become Bea- and eventually collapse orlea-. S-in* eyes or other body parts can bebadly a>ected &burnin/' by corrosive

materials. =cids* halo/en /ases* chlorides*caustic* phenol etc. are corrosive.

(?4 Ha3ard/us P/lymerisati/n + =polymer is a natural or man?made materialformed by combinin/ units called monomers*into lon/ chains. e./. styrene is the monomerfor polystyrene.

Polymerisation is the process of formin/ apolymer by combinin/ monomers into lon/chains. 9ncontrolled polymerisation can beha#ardous* as it can cause heat* pressure ore+plosion. Some chemicals can polymerise on

their oBn Bithout Barmin/* others uponcontact Bith Bater* air or common chemicals.inyl chloride rapidly polymerises in presence

of li/ht* air or heat. Therefore polymerisin/conditions should be controlled properly.Inhibitors&ne/ative catalysts or compoundsthat retard or stop an undesired chemicalreaction such as polymerisation* o+idation*corrosion etc.' are normally added to products

to reduce or eliminate the possibility of ha#ardous polymerisation.

(14 Pyr/9h/ric #aterial + =ny li:uid orsolid that Bill i/nite spontaneously in air atabout 4.4 ;C &13; ;5'. Titanium dichlorideand phosphorous are e+amples of pyrophoricsolids* tributylaluminium and relatedcompounds are pyrophoric li:uids. Sodium*butyllithium and lithium hydride arespontaneously Hammable in moist air as theyreact e+othermically Bith Bater. Suchmaterials must be stored in inert /as or under-erosene. Some alloys &barium* misch metal'

are called pyrophoric because they spar-Bhen sli/ht friction is applied.

Pyrotechnic materials mean (reBor-s.Catalysts of pyrophoric material Bhich

can burn in normal air* are replaced in theatmosphere of nitro/en blan-etin/. TheBor-ers have to Bear self?breathin/apparatus Bhile doin/ such Dob* because inthe atmosphere of about 7;G nitro/en*o+y/en is insuFcient for breathin/.

('4 !idiser and Per/ide + It is acompound that spontaneously evolves

o+y/en either at room temperature or undersli/ht heatin/. +idisers include pero+ides*chlorates* perchlorates* nitrates andperman/anates. These can react vi/orouslyat ambient temperatures Bhen stored near orin contact Bith reducin/ materials &that Billremove o+y/en or add hydro/en' such ascellulosic and other or/anic compounds.Stora/e areas should be Bell ventilated and-ept as cool as possible.

2ero*ides release atomic &nascent'o+y/en readily. They pose (re ha#ards incontact Bith combustible materials*especially under hi/h temperature conditions.

They are used as o+idisin/ a/ents* bleachin/a/ents and initiators of polymerisation.

+idi#in/ substances are not necessarilycombustible in themselves but by /ivin/o+y/en they contribute to combustion of other materials.

6rganic 2ero*ides contain bivalent ;?;?structure* are thermally unstable and mayunder/o e+othermic self?acceleratin/decomposition.

((4 Chemical Sta;ility + = stable compounddoes not easily decompose or react readily.

Chemical stability is the ability of a materialto remain unchan/ed in the presence of heat*moisture or air. =n unstable compound may

16


17/126

decompose* polymerise* burn or e+plodeunder normal environmental conditions.Special precautions are re:uired to store orhandle unstable materials. 5or e+amples* CS2decomposes in li/ht and burns due to heat*spar-* Hame or friction and /ives o> to+ic

fumes of S+. Caprolectum liberates N+fumes due to heatin/. TNT e+plodes due toheavy shoc- or by heatin/. Thus conditionsdisturbin/ stability must be -noBn.

()4 Inc/m9ati;ility + Compatibility meansthe ability of tBo or more materials to e+ist inclose and permanent association inde(nitely.i:uids and solids are compatible if the solidis soluble in the li:uid. ,ater is compatibleBith alcohol &because it is miscible' but notBith /asoline &e./. petrol'.

Incompatibility means disability to co?e+ist permanently. Therefore incompatible

materials should not be stored or -eptto/ether. 5or e+ample* toluene reactsviolently Bith some acids* plastic or rubber*therefore* these substances should be -eptaBay.

Incompatible materials can cause a (re*e+plosion* to+ic release* violent reaction*polymerisation or destroy the structure orfunction of a product. This information isuseful for stora/e and handlin/ purposes.

(*4 Reacti5ity + TBo or more chemicals canreact Bith each other and /ive reaction

products. e./. 2"2 V 2 R 2"2. = sin/lechemical can react Bith air or Bater &Bhichare also chemicals' and /ive the product. e./.phosphorous burns in air and /ives its o+ides&P23* P2'* sulphur burns and /ives S2 etc.

0eactions are e*othermic Bhen theyevolve heat and are endothermic Bhen theyneed heat to maintain them. = reversiblereaction is one in Bhich the reaction productis unstable and /oes bac- to the ori/inalsubstance spontaneously.

In %S)S Be are concerned Bith theha#ardous reaction or reactive material Bhichcan cause (re* e+plosion* to+ic release or

violent reaction Bith air* Bater or commonchemicals or under environmental conditions.Phosphorous* CS2* Sodium metal* acids&reactive Bith metals' etc. are -noBn for theirreactivity. This information is useful forstora/e* handlin/ and process safetypurposes.

(,4 Ha3ard/us Reacti/n Pr/ducts + Thesemust be -noBn for the safety of process*Bor-ers and environment. "ere products aremore important than the reaction because of their ha#ardous nature. e./. Chlorine reacts

Bith alcohol and forms e+plosive al-ylhypochlorite. If to+ic fumes are to be/enerated* scrubbers are re:uired* if

Hammable vapours are /enerated* inert /asblan-etin/ is re:uired and earthin/ of thevessel also becomes necessary. If reactionproducts are hi/hly poisonous li-e NaCN* "CNetc.* they are to be handled in a closedsystem.

(4 Health Ha3ard $ata + 5or T* ST6*I)"* )@C etc. see Part !.* for routes of entry see Part !.!* for e>ects of e+posure seePart !.$* for en/ineerin/ controls see Part!.12.2 and for health ha#ards see Part !.1* allof Chapter?24.

5or emer/ency and (rst aid treatmentand antidotes see Chapter?2!* for (re andN5P= &National 5ire Protection =ssociation of 9S=' Code see Part 4.4 of Chapter?13* forventilation see Chapter 1; and for personalprotective e:uipment see Chapter?2.

T and ST6 are /iven in 2nd Schedule of

the 5actories =ct. ); and C; are /iven in1st Schedule of the %SI"C 0ules for thepurpose of maDor accident ha#ard. ); forinsecticides are /iven in 0ule 17 of theInsecticide 0ules for labellin/ purpose. oBerthese values* hi/her the to+icity. ); up to2;; m/@-/ and C; up to 1; m/@l can causemaDor ha#ard. ective PP6 must be Born by theBor-ers. =bove ST6* S


18/126

3. Cleanliness is a basic re:uirement for safeBor-in/ Bith chemicals. 6mission of dust*vapours and /ases* and the spilla/e of li:uids and solids can be lar/ely eliminatedby careful Bor-in/. ocal ventilationinstallations must be used. Implements

should be cleaned immediately after use.4. Chemical substances should alBays beused e+actly accordin/ to the Brittenprocedure. =nyone deviatin/ from theprocedure on his oBn responsibility is adan/er to himself and others.

. Chemicals should only be used Bhen thedrums* sac-s* containers or pipelinescontainin/ them are clearly labelled.6nsure that the product name anddelivery number on the drums and on thedelivery note coincide. Thou/h appearancealone is no /uarantee of correct identity* avisual chec- should be made. In case of

doubt* or Bhen a mi+?up has actuallyoccurred* a report must be madeimmediately.

!. %any hi/hly reactive chemicals may onlybe used under strictly controlledconditions. 5or substances Bhich reactviolently Bith Bater* the Bater contactshould be avoided.

$. Substances Bhich decompose dan/erouslyunder the inHuence of air* elevatedtemperature* impact or pressure* orcontact Bith catalysts* appropriate safetymeasures contained in the Britten

procedure should be folloBed. )ry at loBtemperature. 0elease the vacuum invacuum dryers Bith an inert /as instead of air. )o not open the drier before roomtemperature has been attained. 0eleasethe vacuum in vacuum distillations Bith aninert /as. 6+pose distillation residues tothe air only Bhen cold. "andle and storecatalysts only under the specially de(nedconditions. Prevent compounds Bhich areparticularly prone to decomposition &e./.certain dia#o?compounds' from dryin/ out&lea-s* splashes'.

. Substances Bhich i/nite spontaneously

e./. Bhite phosphorous* pyrophoriccatalysts etc. should be handled under aninert /as or li:uid. ,here necessary Bearspecial protective clothin/. Meep theprescribed means of e+tin/uishin/ onhand.

7. Prevent the possibility of dan/erouscombinations. 5olloB the Britten procedureprecisely. ,hen preparin/ Bor-* ensurecomplete separation of compounds Bhichare dan/erous Bhen mi+ed.

1;. Not only actual e+plosives* but alsonumerous Bidely used chemicals can

e+plode Bhen e+posed to catalysts* heator impact. 6+amples 8 acetylene andderivatives* acetyl nitrate* acrylic acid and

its esters* ethylene o+ide* a#ides*a#omethane* pero+ides* chlorates*perchlorates* cyano/en chloride* hydro/encyanide* hydra#ine derivatives* o#onides*propar/yl alcohol and other propar/ylcompounds* hydro/en a#ide etc. The

handlin/ of such compounds is /overnedby special safety measures* Bhich are tobe found in the Britten procedures.

11. Chemicals Bhich are spilled orcontaminated should not be simplydiscarded in the refuse bin* but disposed of accordin/ to instruction from thesupervisor.

12. The :uantities of chemicals stored in achemical plant at any time should be -eptto the minimum re:uired for normalBor-in/.

13.


19/126

"W igns and symptoms li-ely to bemanifested on e+posure to ha#ardoussubstances and to Bhom to report.

IW %easures to remove spillage or lea>ageof ha#ardous substances.

LW 0ole of the Bor-ers in the emer/ency

plan and evacuation procedures.MW =ny other information necessary toensure safety and health of Bor-ers.

4. uantity of solid* li:uid and /aseouswastes /enerated per day* theircharacteristics and methods of theirtreatment and disposal XS.41?


20/126

1 =mmonia- anhydrous- li:uid*

shipment

%SSteel container

17 5ruit Duices* mil-and mil-products

Nic-el

2; CCl4 SS* tin* hi/hsilicon iron &14GSi'

21 =l-aline solution Nic-el22 Pressure vessel

operatin/ at ;;atm and ;; ;C

%olybdenum SS

23 To pump causticsoda* chlorinatedbrine orhypochlorousacid

0ubber linedpumps

24 0otary dryers %S

2 Aobar /as plant- di/ester- /as holder

%asonry Bell%S

2! Co-e oven- Ball linin/- re/enerator

s

Silica bric-s5ire clay bric-s

2$ 5ermentor toproduce ethylalcohol frommolasses

Copper bearin/steel

2 0eactor toproduce PC

Nic-el or /lasslined steel

27 Tubes for

multiple e>ectevaporator forconcentration ofsu/arcane Duice

Copper

3; Ceramicrecuperators

Silicon carbide

31 Protection fromrustin/

AI sheet

32 5luorine* dry Copper vessel

Ta;le 184* + N/n Suita;ility /f #aterials

N/4

St/ra7e /rPr/cess

N/n Suita;le#aterial

1 "2S4 ? ; G

concentration=luminium* %S*SS* tin* concrete

? 1;;G at 3; ;C =luminium* tin*rubber

2 "Cl 1;G* 5errousSulphate*=:uare/ia

=luminium

3 "Cl Uconcentrated

"i/h Silicon castiron &Si 14G'

4 ,et S2 CI vessel "2S4 U 7G or

6therSilicon rubber

! 5luorine* dry orBet

Alass

$ "Cl* S2* Cl2 ,ood

=l-aline solutions Centrifu/al pumpof pyre+ or /lass7 "5 a:ueous at

1;; ;CSS

1; =cetic acid 4; ;C


21/126

7au7e Ru9ture$isc

1 Sulphuricacid

%S Yes 5loat No No Simple vent Centri?fu/al

2 "ydro?

chloric acid

%S0 or

50P

Z Z Z Z ent Bith

Baterscrubber

Z

3 Nitric acid4G

7G

%S* loBcarbon

=luminium

Z Z Z Z ent Bithcaustic

scrubber

Z

4 =l-ali %S Z Z Z Z Simple vent Z leum

23G !G%S Z )ial

meterZ Z ent in

sulphuricacid tan-

Submersi?ble or

centrifu/al! 5ormaldeh

yde 3$G%S Z 5loat or

)ial Yes Yes ent Bith

Baterscrubber

Centri?fu/al

$ =mmonia&P $ to 12

bar'

Steel&doubleBall for

refri/erated

stora/e'

Z %a/netic Hoat*

di>erential

pressure* Bithalarm

[ Yes*doubl

eSafetyalve

ent athei/ht or

Baterscrubber

Pressure

Chlorine &P$ to 11

bar'

%S Z Z Yes*double*

Bithhi/h*loB

alarm

Z ent Bithcaustic or

limescrubber or

Hare

)ry airpressure

7 PA &P 2 to

$ bar'

"i/h

tensilesteel

No.

Slopeand

fence

)ial

/au/e

Yes Yes ent Bith

Hare

Pressure

1; 5lammableli:uid@solvent

%S&SS for

%ethanol'

Yes CloseHoat or)ial or

)P

Yes if storedcold

Yes if inertblan-etin/

ent BithHame

arrester orbreather

valve

Centri?fu/al

utlet valve should be -ept on side Ballinstead under the bottom to facilitaterepairin/ and maintenance. 6mer/encybypass system should be -ept ready.

To prevent escape of bul- stora/e remoteoperated isolation valve should be providednear outlet valve* drain point* (llin/ point*pumps suction etc.

Non return valves &N0' are useful toprevent reverse HoB and e+cess HoB valve&65' to prevent e+cess HoB. If they are notfully reliable* shut o> valves should beprovided at critical service.

Tendency of purchasin/ second hand orold?repaired &fabricated Bith patchBor- andBeldin/' tan- or vessel and to (t it to neBre:uirement is an unsafe practice.

5or corrosion prevention* tan-s and

pipelines should be coloured Bith anti?corrosive paints.


22/126

other emer/ency control activity. Thecontained material can be safely disposed o> or if it is burnin/* it can be e+tin/uished easilyby reachin/ upto dy-e Ball. If there is no dy-e&or bund' the lea-in/ material can come onthe road or /o in the plant and ma-e more

dama/e.erent Hashpoints can be -ept se/re/ated.

)y-e Ball should be safe* sound andlea-proof. Its Hoor should have a slope Bith apit in corner to provide a dischar/e valveBhich should be opened only Bhen the rainBater or the stored &lea-ed' chemical is to besafely dischar/ed. The volume of the dy-eshould be sli/htly more than the bi//est tan-inside. ,all hei/ht should be less than 2 mt&mostly 1 mt' for ease of (re (/htin/ andmaintenance Bor-. Steps should be provided

to /o inside. =cidproof linin/ should beprovided Bhere re:uired.

)y-e is alBays re:uired if the li:uid isstored at the atmospheric or loB pressure andtemperature. 0efri/erated chemical Bhenlea-s* it remains li:uid till it reaches itsboilin/ point. Therefore dy-e is re:uired for it.e./. refri/erated ammonia.

5or hi/hly volatile /ases or /ases at hi/hpressure* dy-e is not much useful and Birefencin/ is provided at a safe distance. 5ore+ample* PA* NA* butane* butadiene*propane* ethane* methane* ethylene*

ethylene o+ide* hydro/en* acetaldehyde etc.are -ept under vapour pressure Bhere at thetime of lea-a/e* they spread rapidly andtherefore their tan-s are -ept in open at asafe distance Bith fencin/ on four sides. TheHoor under such tan- is /iven a slope so thatdrippin/ li:uid may run aBay to avoid (re Dustunderneath the tan-.

,hile openin/ dy-e dischar/e valve of aHammable material* spar- should be avoidedotherBise (re can travel inside the dy-e andcatch the tan-.

,here possibility of e+plosion is there*impact or blast Ball &thic-* sound' should be

provided near the tan-.

84'4) Se9arati/n $istances +Some recommen?dations are available to

-eep minimum safe distance* -noBn asseparation distance* betBeen tBo tan-s orbetBeen tBo /roups of tan-s or betBeen atan- and a buildin/ or betBeen a tan- and asource of i/nition.


23/126

ventilation should be alloBed. 5irst it shouldbe e+ternally e+amined for manual chec-sand then it may be hydraulically or pressuretested. Test record should be maintained.

84'4, Pum9-transfer +

i:uid should be transferred by pump andnot by any air pressure or truc-?en/inee+haust. Submersible pump at the top ismore safe as it avoids the bottom valves and

Doints. Pressurised /ases are transferred bytheir oBn pressure. 6arthin/ of the tan-*pump?motor and the truc-?body are essential.


24/126

tonnes' have " &hi/h' and "" &hi/h?hi/h'level alarms i.e. double alarms for doubleBarnin/ before reachin/ the hi/hest level.oB level alarm is necessary Bhere minimumlevel must be maintained. =t that level thefeed pump should automatically start.

The level alarm and feed?trip device&interloc-' is a substitute of overHoB pipe butif this device fails* an accident is possible. =simple overHoB pipe is a safer en/ineerin/control. "oBever the Dud/ement depends onmany other factors &e./. type and :uantity of material* storin/ parameters* HoB* ha#ard*other safety* instrumentation and controletc.' and technical re:uirements.

84'4= "illin7 Rati/ += tan- should not be (lled beyond its (llin/ratio &0f' /iven as under ?

C R 0f R

,hereC R CoeFcient of cubical e+pansion of li:uid)1 R )ensity of li:uid at 1 ;C)r R )ensity of li:uid at Tm

Tm R %a+imum bul- temperature ;C Tf R 5illin/ temperature &mean' ;C

5illin/ ratio or (llin/ density is le/allyde(ned as the ratio of the Bei/ht of thematerial &li:uid or /as' to the Bei/ht of theBater that the tan- Bill hold at 1 ;C &See

part 2.12 of Chapter?2'.

84'41? e5el Indicat/r + The :uantity &measure' of the material in

the tan- should be e+ternally visible so thatits e+cessive &unsafe' (llin/ can be avoided*minimum loB level can be maintained and anorder for ne+t re:uirement can be placed.

=n old manual method is to measure thelevel by a dip?rod &calibrated yardstic-'insertin/ it from the top of the tan-. This maybe alloBed for small or medium si#e tan-s&upto 1; or 2; tonnes as in case of rail or roadtan-ers'. If the content is Hammable* the rod

should be non?metallic or it should passthrou/h non?spar-in/ linin/ of the hole&no##le' to avoid spar- Bhile movin/ the rod.)ip rod system re:uires a Bor-er to climb onthe top of a tan- and that is its disadvanta/e.erential pressure* displacer* oscillator*electric* electronic and computerised control&from a control room' type direct readin/ levelindicators are available in variety and they

can be interloc-ed Bith other re:uirementsalso. They should be selected as per needdependin/ on the type of content to bemeasured &e./. sp. /ravity* viscosity* colour*pressure* temperature* HoB* Huctuations etc.'

i-e pressure and temperature indicator*reliability &:uality' of a level indicator ise:ually important* otherBise it may lead toan error and accident. Therefore it should beensured Bhile purchasin/.

84'411 Pressure Relief $e5ices +If pressure inside a tan- rises due to any

reason* it may burst the tan- from its

Bea-est part or cause lea-a/e from Bhere itis possible. The content thus comin/ out is amaterial loss and in addition* it may create(re* e+plosion or to+ic ha#ard. Therefore toavoid such situation a pressure relief device isnecessary.

= safety valve is a common pressurerelief device. It can be set to a predetermined&desired' pressure and Bhen pressure e+ertedon it e+ceeds that pre?set value* itautomatically opens and alloBs the pressureto release in the atmosphere or in a catch?potor droBnin/ tan- if the content comin/ out is

hot or ha#ardous. It automatically closesdoBn also* after release of the e+cesspressure. Safety valves are of four types ?sprin/ loaded* Bei/ht lever* solenoid andpilot. Safety valves are used to release /as orvapour but not the li:uid.

= Ru9ture $isc is re:uired for the fastrelease or more HoB from a bi//er si#e holeor if internal pressure is too hi/h or too rapidor the material is stic-y and cho-es the safetyvalve. This disc is selected based on manyparameters &e./. type of chemical* Bor-in/pressure* temperature* reaction* material of the tan-* viscosity* corrosivity* to+icity and

Hammability of the content etc.' ne disc canbe used for one pressure i.e. its set?pressurecannot be chan/ed li-e safety valve* andafter rupture the same disc cannot be reused.nce opened* it cannot reset at the loBeredpressure li-e safety valve* and Bill alloB theBhole mass to come out till the hole is closedor the disc is replaced. This is itsdisadvanta/e. Therefore* it is inadvisable ontan-s containin/ Hammable /ases or li:uids.0upture disc can be used in conDunction Bitha safety or relief valve. Then the disc Billburst (rst Bithout a>ectin/ the valve. If

pressure is further built up* then the valve Billopen. Pressure /au/e is provided betBeenthe disc and the valve to indicate that the

24

)1 ? )r)r &Tm ? 1' 71 V C &Tm? Tf'


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disc has opened and Bhat is the burstin/pressure. Imperfections in manufacture*installation or caused by corrosion can resultin premature failure of the disc. The rupturediscs are used to release /as* vapour orli:uid.

elief valves do not full open at setpressure li-e safety valve* but open sli/htlyand then open further as the pressureincreases. They are of tBo types ? sprin/loaded or poBer actuated by electric* air*steam or hydraulic poBer activated by apressure sensor in upstream of the valve.%anually operated relief valves &li-e ventvalve' are also possible but they are to beoperated after seein/ the pressure in thepressure /au/e or after hearin/ an alarm.0elief valves are used for li:uid dischar/e andnot for /as or vapour.

afety'relief valves can be used either as

a safety valve or a relief valve* dependin/ onthe application. They are used for /as* vapourand li:uids.

(usible plug is a (ttin/ (lled Bith an alloythat melts at a predetermined temperature&not pressure' and /ives Bay to the materialto come out. 5usible plu/s are used in boilers*domestic pressure coo-ers and compressed/as cylinders to prevent violent burstin/.

They are used for /as* vapour and li:uids of hi/h temperature.

(ire or )*plosion elief is provided byma-in/ the seam betBeen the shell and the

roof of the tan- deliberately Bea- so that itmay rupture (rst and the shell stays intact.5acuum brea>er is also a type of pressure

relief device and Bor-s li-e a sprin/ loadedsafety or relief valve but in the reverseddirection. The outside atmospheric airpressure bein/ hi/her than that inside thevessel* opens it to brea- the vacuum. This isre:uired Bhen the vacuum may increase tocollapse the vessel. This device is used for aironly.

Thus a relevant pressure relief device canbe selected from above discussion. )oubleSafety alves are re:uired for bul- stora/e

tan-s of chlorine* ammonia* PA* ethyleneo+ide etc.* for the purpose of double safety. Inthat case there should be sli/ht di>erence intheir pressure settin/s so that functionin/ of both the valves can be veri(ed by their oneby one openin/ or no need arisin/ tofunctionin/ by the second valve as the (rstopened safety valve Bor-s eFciently.

,here tBo or more safety valves areprovided* their isolation valves are alsoprovided to replace them Bhile -eepin/ atleast one on the line. In such case* isolationvalves on the line should be -ept loc-ed

open so that they cannot be closedun-noBin/ly or Bithout authority.

If addition is controlled* pressure can alsobe controlled. In nitration process addition of nitric acid should be at a sloB or controlledrate* otherBise rapid pressure rise can burstthe vessel. Safety valve may not be useful inthat event. =n eFcient HoB controller

&automatic re/ulator' or an e+cess HoB valveBith a niddle valve &for (ne control' should beutilised in such condition* alon/ Bith thepressure relief device.

It is better and safer to -eep the pressureunder control by controllin/ heat source*temperature or the rate of reaction.

14'41'4 "lame9r//f "ittin7s +6lectric (ttin/s li-e motors* starters*

sBitches* lamps* tubes etc.* near the stora/etan-s containin/ Hammable materials &seefore/oin/ Part $.3 for de(nition' should be of approved Hameproof types and conformin/ to

Indian Standards li-e 214* 4!71* $1* $;*$!73* 237* 24; etc.

5lameproof electric (ttin/ is mostessential if the material is havin/ Hash pointless than 23 ;C or if it is to be heated upto orabove its boilin/ point* and also in case of solvent distillation. See Part of Chapter 11and Part !.4 of Chapter 13. ther sources of i/nition from Beldin/* cuttin/* open Hame*smo-in/* spar-in/* friction etc. should also beavoided.

84'41( Earthin7 6 B/ndin7 +

Tan-s and pipin/ containin/ Hammablesubstance should have double earthin/s of appropriate type. 6arthin/ pit should berechar/ed periodically for easy HoB of thecurrent. 0esistance should be measured&beloB 1; M?ohm' and recorded. IS83;43 isuseful for earthin/ code. 5illin/ &inlet' pipeshould be e+tended upto bottom or an innerlimpet coil should be provided to avoid freefall and static char/e due to material HoB.

Pipe Doints@Han/es should have copperbondin/ to maintain electric continuity.5lan/e?/uard is useful to divert the lea-a/edoBnBards.

,hile loadin/ or unloadin/ Hammableli:uids or /ases* the vehicle &road or railtan-er' should also be earthed durin/ suchoperation.

84'41) Pr/tecti5e #edia +oB?boilin/ chemicals &e./. %ethyl

bromide* ethylene o+ide* ethylamine'* to+ic/ases &e./. chlorine* phos/ene* "CN* N"3' orpolymerisin/ materials &e./. %IC* styrene*acrylonitrile' should be -ept beloB theirboilin/ point@Hash point. 5or this purposeeither under/round tan- or insulation* or

Dac-et and brine circulation* or refri/eration*or Bater shoBerin/ etc. are employed.


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and refri/erant /ases are protective coolin/media.

Chemicals of hi/her meltin/ point &e./.phthalic anhydride* dinitro ben#ene*naphthalene' are to be -ept hot above theirmeltin/ point for their easy HoB in li:uid

state. 5or this purpose steam Dac-et* limpetcoil or tracin/s are used. "ere steam is aprotective heatin/ medium.

5lammable chemicals or solvents of loBboilin/ or Hash points need inert /asblan-etin/ &e./. N2* C2'. 5or e+amples*acetaldehyde* acrylonitrile* ben#ene* 6* "2Setc. need such inert /as blan-etin/ toprevent spar- contact and (re. ,hen a safetyor breather valve opens* (rst inert /as comesout and not the Hammable vapour. "ere inert/as is a protective medium.

Chemicals Bhich catch (re in air &e./.phosphorous* CS2' are to be -ept in Bater and

chemicals Bhich e+plode in Bater &e./.sodium metal' are to be -ept in -erosene andprotected. "ere Bater and -erosene areprotective media.

,ater curtains* sprin-lers &spray no##les'and remote operatin/ valve are provided forchemicals li-e acetaldehyde* ammonia* "CN*Bhere Bater can dissolve their vapour and-eep the tan- cool in case of (re. ,ater canalso be used as a scrubbin/ medium for suchBater soluble /ases.

,ater sprin-lers should Bor- at a rate of 1; it@m2@min. 5oam inDection system &in

atmospheric tan-s' should Bor- at a rate of 4. it@m2@min to e+tin/uish the (re. Thermal insulation &e./. vermiculite

cement of 2 inch thic-ness' for pressurestora/e and P95 insulation for refri/eratedstora/e are also useful.

Thus selection and application of appropriate protective media for chemicalsare alBays desired for safety of their stora/eor processes.

84'41*4 Pers/nal Pr/tecti5e and "ire"i7htin7 EFui9ment +

,hile Bor-in/ at stora/e* process* handlin/*

use or transfer of chemicals* appropriatepersonal protective e:uipment &helmet*/o//les* faceshield* /loves* boots* apron*respirator etc.' should be Born by Bor-ers toprotect themselves in case of any accidentaldischar/e or e+posure. Similarly a trained (re(/htin/ team is also re:uired to useappropriate (re (/htin/ e:uipment. Trainin/for use and maintenance of such e:uipmentis most essential. See Chapters 2 and 13 forPP6 and 556.

84'41, :au7es@ Val5es@ Rem/te and Aut/

C/ntr/ls84'414 #iscellane/us +

Stora/e safety is a Bide subDect andincludes so many thin/s. )espite abovediscussion a feB thin/s are to be mentioned.

There should be minimum connections to atan-. Pipe Doints should be safe and sound.Sti>eners and other supports should be

properly provided. Staircase Bith handrailand Bor-in/ platform should be provided onthe tan-. 5or ha#ardous chemicals in bul-*the main outlet valve should be remotelycontrolled. 9nloadin/ bay should have readyconnections Bith tan-farm pipin/ and (+edlocation for truc-@tan-er par-in/. Tan-ercarryin/ Hammable material should havespar-?arrester &muJer' over his e+haust pipe.

)ump vessel &one empty tan- of theidentical desi/n to the stora/e tan-' shouldbe installed Bith ready connections totransfer the content in case of emer/ency. If possible* desi/n should be to transfer by

/ravity.Pump should be of proper desi/n and

capacity. )ouble mechanical seals should beprovided to avoid /land lea-a/e. 5lan/e capon Han/e?Doint can divert the lea-a/edoBnBards. Necessary drain and samplepoints should be provided.

In acids and al-ali tan-farm* acidproof linin/@Hoorin/* Bater shoBers* cautionarynotice* mechanical liftin/ device &e./. trolley'and necessary PP6 should be available. 5orspill control lime* sand* soda ash and ampleBater should be readily available.

Near tan-s of to+ic or Hammablematerial* /as and Hame detector Bith alarm*hi/h pressure@temperature alarm* autocontrollers* necessary scrubber or Hareconnections* 556* PP6* /ood li/htin/ andventilation* safety shoBers* dy-e* connectionsto 6TP &6Juent Treatment Plant'* emer/ency&alternate' poBer and Bater supply*emer/ency -it and tools* li/htenin/conductor* Bind soc-* etc. should be providedas per re:uirement.

%odern sophisticated plants are run bylatest control rooms Bhere all processparameters are controlled and recorded from

this control room. The latest instrumentationand computer control technolo/y &e./. )CS' isutilised.

84( Pressure Vessels and theirSafety

As9ects +

Pressure vessels are of tBo types 8 &1' 5iredPressure essels Bhich include


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containers* compressors* vulcanisers* a/ers*-iers* dyein/ vessels* Dac-eted -ettles etc.operatin/ above the atmospheric pressure.

The portable /as cylinders* metal bottlesused for stora/e or transport of compressed/ases or li:ue(ed or dissolved /ases under

pressure* /as?tan-ers* vessels for nuclearener/y* refri/eration plant of less than 3 TP)capacity* vessels operatin/ beloB 1 -/@cm2

etc.* are not covered under the purvieB of thepressure vessels.

84(41 Pressure System C/m9/nentsand Safety $e5ices

Pressure system components are 8

Pressure vessels Pressure reliefdevices

Pumps*Compressors*

Pressure /au/es

5ans* Controlvalves*

Pressure reducin/ valve &P0'

Pipin/ system* Tracin/)ump vessels* Non?return valve

&N0'Steam traps*Insulation Pressure controllers

or re/ulatorsent for pressurerelief 9tilities li-e steam*

Bater* air* thermicHuid* inert /as etc.

Pressure recorders

See para 11 of fore/oin/ Part 7.2 forvarious types of pressure relief devices. thercomponents are e+plained at their respectiveplaces.

Pressure reducin/ valve &P0' is astatutory re:uirement u@r !1 of the AuDarat5actories 0ules. It is to be provided betBeen asource of supply of pressure &e./. boiler orhi/her pressure side of any header' and theuser point or a vessel receivin/ the pressure.It is to be set at a desired safe pressure. ItBill reduce the pressure on delivery sideaccordin/ly. This is the main safety function.

= safety valve and a pressure /au/e shouldbe provided on loB pressure side and apressure /au/e on hi/h pressure side to seethe pressure reduction. It shall not bebypassed at any time. It should be testedperiodically.

Sprin/ loaded safety valves Bith oil sealsare desirable. 5or hi/h pressures* rupture orburstin/ disc or rupture diaphra/m shouldalso be provided. Pressure reducin/ orpressure control valves are necessary. Safetyvalve and pressure /au/e should beconnected on loB?pressure side of thereducin/ valve. Safety valve should beconnected nearest &close' to the vessel. It

should not be connected Bhere pulsatin/pressure Huctuates.

0upture or burstin/ disc should beprovided in upstream of the safety valve andif to+ic or inHammable mi+ture@/as is pressed*ductin/ should be provided coverin/ fully the

outlet of the rupture disc so that in case of rupturin/ of the disc* the mi+ture@/as comin/out from it Bill be collected in duct or bloBdoBn tan- and not in environment.

0upture disc and safety valve can beprovided in series &in vertical line of the sameoutHoB' Bith a pressure /au/e in betBeen.

TBo such sets can be provided side by side*parallel* on tBo di>erent outHoBs* to handlemuch volume at a time. 0) and S can beprovided in parallel also. In any case* theirsettin/ should be sli/ht di>erent to alloB timela/.

5usible plu/s* pressure /au/es*

temperature indicator* stop valve* drainvalve* air vent* auto controls and recordersare also necessary.

0outine inspection schedules should bedevised for maintenance of pressure safetydevices in /ood Bor-in/ order. = sampleschedule re/ardin/ rupture disc inspection is/iven beloB as a /uidance.

R/utine ins9ecti/n /f ru9ture discs

Procedure:

1. btain Permit to ,or- Certi(cate fromPlant in?char/e.2. btain 0upture )isc Inspection 0ecord

sheet.3. 6nsure system to be Bor-ed on is

isolated* free from pressure andvented@drained doBn.

4. Chec- that vent line drain hole is clear.Note 8 If no drain hole e+ists raisemodi(cation Bor- order to ma-e one.

. Carefully remove rupture disc and holderensurin/ no debris enters vessel* andclean thorou/hly.

!. Chec- that all burstin/ disc speci(cations

are correct.$. Inspect rupture disc holder for pits*

hairline crac-s or other dama/e andreneB if necessary. 6nsure inspection iscarried out usin/ ade:uate li/ht.

. 6nsure rupture disc inlet and outlet ventsare clear and free from obstruction.

7. Chec- mountin/ Han/es are clean andparallel.Note 8 The Team %ana/er must assessthe si/ni(cance of the conditions foundand arran/e* if necessary* to revieB thefuture maintenance periodically.

1;. 0eneB /as-ets and re(t rupture disc andholder* ensurin/ disc is correctlyorientated.

27


28/126

11. Carefully ti/hten dia/onally opposite boltsto achieve a /as ti/ht seal* usin/ tor:ueBrench if necessary.

12. 6nsure plant is safe for use* completepermit to Bor- and hand over to Plant in?char/e.

Rupture Disc Inspection Record

Ru9ture $isc $etails

6:uipment no.ing 2ressure$32A2 means the ma+imum pressure atBhich a pressure vessel or plant is permittedto be operated or used under this rule and isdetermined by the technical re:uirement of the process.

Sc/9e + This rule applies to a pressure vesselor plant operatin/ above the atmosphericpressure and includes pipin/ system.

The rule does not apply to '

1. essels operatin/ at a pressure beloB 1M/@cm2.

2. ,here Indian


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2. Suitable pressure /au/e Bith dial ran/e1. times the %P,P and red mar-indicatin/ %P,P.

3. Stop or isolation valve to shuto> thepressure source.

4. )rain coc- &valve' to drain the vessel.

. Suitable pressure reducin/ valve &P0' orautomatic pressure re/ulator to disalloBthe pressure /reater than the %P,P. =safety valve shall be (tted on loB pressureside of such device.

84(4( "undamentals /f PressureVessel $esi7n

IS822* Section I includes in its 9esignsection* Aeneral Provisions* Corrosion* erosionand protection* Cylindrical and sphericalshells* )omed ends* Conical ends* 9nstayedHat heads and covers* Stayed and bracedplates* penin/s branches and compensation*=ccess and inspection openin/s*


30/126

Pressure e+ceedin/ the ma+imum permissibleBor-in/ pressure &%P,P' of a pressure vesselposes hi/h ha#ard and needs pressure relief devices.

See para?11 of fore/oin/ Part 7.2 Bhere

such devices on stora/e vessels arediscussed.0ule !1 of the AuDarat 5actories 0ules

&see fore/oin/ Part 7.4.2' re:uires safetyvalve or pressure relievin/ device* suitablepressure /au/e* stop or isolation valve toshut o> pressure source* drain valve* pressurereducin/ valve or automatic pressurere/ulator. In Chapter 2* other safety laBsre:uirin/ such provisions are also discussed.

IS822* Section I* Part /ives muchdetails on this subDect. It re:uires as under ?

1. 5ully li:uid (lled vessels should have li:uid

relief valve.2. If a vessel is (tted Bith a heatin/ coil or

element* pressure increase due to itssudden failure* should be considered Bhiledesi/nin/ relievin/ capacity of theprotective device.

3. essels operatin/ under vacuum shouldhave a vacuum brea- relief device.

4. essels operatin/ under pressure andvacuum &due to coolin/ of content' both*should have a combined pressure?vacuumrelief device.

. Pilot or other indirect control valve alone

are not permitted. %ain valve openin/ at aset pressure automatically must beprovided. The relief valve shall be sodesi/ned that they cannot beinadvertently loaded beyond the setpressure.

!. ect of static head and constant bac-pressure. If more than one protectivedevice is provided* only one be set at%P,P and other devices at pressure notmore than G in e+cess of the %P,P.

7. apour relief valve shall be provided invapour space and li:uid relief valve inbeloB the li:uid level.

1;. )ischar/e line &after relief device'diameter shall not be less than that of therelief device outlet. Si#e of draina/e orbloBdoBn tan- should be such that it Billnot reduce the relievin/ capacity of therelief device. )ischar/e lines shall beproperly anchored* particularly at theiropen ends* not to alloB any displacement.See Part 7.4.1 also.

et us see some practical e+amplesBhich can cause accidents. ,here a pumpfeeds a receiver* the safety valve should passthe volume bein/ pumped if it has to open. Indistillation column Bhere normally there is nopressure* overpressure may be created due toincreased heat input because of coolin/failure or loss of reHu+ or loss of subcooledfeed and increase in temperature di>erence

in reboiler. Therefore safety valve becomesnecessary on distillation vessel or column.oB pressure stora/e tan-s can Bithstand avery loB pressure. Safety valve should beprovided on it to tac-le any accidentalpressure rise. Safety valve of loB pressureside of a heat e+chan/er should be si#ed tohandle the HoB from tBice the cross sectionalarea of the hi/h pressure tube in thee+chan/er to relieve its sudden burstin/pressure.

To chec- Bhether safety valves operatereliably* they should be daily opened by hand.

The number of safety valves on anyvessel depends on the volume of Bor-in/Huid and dischar/e capacity of the valves.

30


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"i/h noise is created by bloBdoBn of safety valves. 6n/ineerin/ control to reducethis noise are necessary. ,or-ers in safetyvalves testin/ area should Bear ear* eye andhand protections.

Aater eal is used on pressure vessels

that operate at loB pressure or sli/ht vacuumsuch as alcohol stills and /as holders. = 9?pipe (lled Bith Bater Bith one end connectedto the pressure side and other end openBor-s as a loB pressure safety valve.

9epressurising devices or pressureinterloc-s are re:uired on autoclaves*vulcanisers* di/esters* Det dyein/ vessels*retorts etc. Bhere char/in/ doors are to beopened. The device or interloc- Bill preventthe door openin/ till all pressure inside isrelieved or prevent the pressure build?up tillthe door is closed.

+igh pressure alarms /ive audio visual

alarm that the pressure is bein/ increased. They are useful Bhen pressure relief devicemay not Bor-. In that event a vent valve ordischar/e valve should be manually orremotely opened and the reason of non?functionin/ of the relief device at its setpressure should be investi/ated.

2ressureBTemperature recorders orprintouts are useful to study the processbehaviour or investi/ate an accidenthappened on the system.

84) Reacti/n /r Pr/cess Vessels

+


32/126

Small si#e stora/e tan-s and processvessels reduce the ris- :uantity. oBtemperature cryo/enic processes &beloB 2;;;C' need vessels of carbon steel constructionand temperature control and heatin/ deviceto stop further reduction in temperature.

6ndothermic process vessels need heatsupply and maintenance devices.

Reacti/n Vessels 6 ettles + =bstract of 0ule !1< of the AuDarat 5actories 0ules is asunder 8

A99lica;ility + This rule applies to reactionvessels and -ettles Bhich normally Bor-beloB the atmospheric pressure* but Bherethere is a possibility of pressure risin/ abovethe atmospheric pressure due to uncontrolledreaction.

Safety #easures +

1. Temperature control device in case of electrical heatin/.

2. Pressure control device in case of steamheatin/.

3. Safety valve or rupture disc of ade:uatesi#e and capacity to release the pressureabove the safe limit.

4. Suitable vent pipe for safe dischar/e of reaction mass.

. 5lame arrester on vent end if the materialis Hammable.

!. Pressure /au/e of appropriate ran/e.$. =utomatic feed?stop?device to preventdeviation from normal limit to dan/erousone.

. If necessary* e>ective system for coolin/*Hoodin/ or blan-etin/ to controltemperature and pressure.

7. =udio visual Barnin/ devices to indicateprocess deviation. It should be inte/ratedBith automatic process correction system&computer control' if possible.

1;. = notice near the vessel* pointin/ outpressure risin/ conditions and dan/ersinvolved and precautions to be ta-en by

the operators

84* "lare +

In plants Bhere hi/hly to+ic or Hammable/ases are /enerated in bul- or continuously*a Hare system becomes necessary for theircollection and safe dischar/e by burnin/ athei/ht. The Hare should be desi/ned to ventthe /ases durin/ normal operations andemer/ency conditions. %a+imum possibledischar/e at a time should be considered for

safer ventin/ and preventin/ pollution of theenvironment.

= Hare system consists of a Hare stac-and pipin/ to collect the /ases to be vented.=t the Hare tip* steam no##les are providedfor air entrainment and seals to preventHashbac- of the Hame. =t the base a-noc-out drum is provided to collect the li:uid

from the /ases passin/ to the Hare.,et /ases and dry* cold /ases arecollected throu/h separate lines. = loB leveland a hi/h level Hare can be combinedto/ether so that normal operatin/ and start?up loads are handled by the loB level Hare*Bhile both Hares are used to handleoccasional hi/h volume emer/ency loads.

Thus an environmental impact of Harin/ canbe -ept to a minimum.

=n intense heat radiation occurs from aHare. Therefore it should have suFcienthei/ht and no population in surroundin/ area.

The dischar/e heat rate may be of the order

of 1;$


33/126

the Hame and factor 5 R ;.1!* ;.33. ;.3; and;.3 for methane* propane* butane andethylene respectively.

=cceptable heat radiation level at /roundlevel is 1;;;


34/126

1. 9se of standard and correct pressure/au/e.

2. 0emoval of air from the vessel beforetestin/.

3. isual inspection for clearly visible defects

if any.4. 9se of a rupture disc to test at a hi/hpressure.

. Protected area aBay from public. = pit orsteelbo+ is preferable.

!. imitin/ the li:uid volume in the testvessel to reduce the ener/y stored at thetime of testin/. To achieve this* bi//er si#esolid pieces should be inserted in thevessel to ta-e up as much of its volume aspossible.

=fter hydraulic testin/ if more than ;.2Gincrease &elon/ation or deformation' in

volume is noticed* the vessel should not berecommended to use as a pressure vessel.

0'2 Pneumatic Test +

This test is useful Bhere even traces of Batercannot be tolerated in its service or Bhere avessel is so desi/ned and@or supported that itcannot be safely (lled Bith the Bater ortestin/ Huid.

Such test shall be carried out under closesupervision by the inspectin/ authority.=de:uate precautions li-e blast Ball or pit

and means for remote observation areessential. The pneumatic test pressure should be

more than the desi/n pressure but less thanthe hydraulic test pressure. In the be/innin/*the pressure should be /radually increasedupto ;G of the test pressure. Thereafter itshould be increased in steps of 1;G of thetest pressure till the re:uired test pressure isachieved. Then the pressure Bill be reducedupto desi/n pressure and held at thatpressure for a suFcient time to permitinspection of the vessel.

0(2 C/m;ined Hydraulic andPressure Test +

"ere a test vessel is partially (lled Bith Baterand then air pressure is applied to the spaceabove the li:uid level. The test pressure &note+ceedin/ hydraulic test pressure* but morethan the desi/n pressure' shall be deductedby the pressure due to the static head of theBater in the vessel.

84,4' N/n $estructi5e Tests 0N$T2 +

See Part 4.4 of Chapter?17.84,4( Test ;y C/m9etent Pers/ns +

84,4) Rec/rds in 9rescri;ed "/rms +

84 C/rr/si/n@ Er/si/n@ Causes@Ins9ecti/n and Pre5enti/n

Reas/ns /f Pressure Vessel "ailure are

many. ,ron/ selection of material of construction* mechanical failure due tooverpressure* overheatin/* e+ternal loadin/&e./. platform* stairs* ladders* supports*brac-ets etc.'* e+cessive stress &uneven orover ti/htenin/'* brittle fracture* creep &dueto (re or maloperation'* mechanical fati/ueand shoc- &due to pressure or HoB variations*vibrations* e+pansion e>ects'* thermal fati/ueand shoc- &due to temperature di>erence andrate of chan/e of temperature'* hydro/enattac- &blisterin/ or embrittlement' andcorrosion failure are some of the reasons.

C/rr/si/n is an electrochemical reactionbetBeen a metal and its environment. Itresults in a loss of metal or Bea-enin/ of it.Corrosion reaches deeply* createsmaintenance problems and incurs cost of lossin lacs of rupees over the years.

C/rr/si/n failure has also manyreasons to occur. Aeneral* local and e+ternalcorrosion* /alvanic* crevice* -nife?line*inter/ranular and stress?related corrosion*scalin/* e+foliation* corrosion pittin/ anderosion are some common types of corrosionin process plants includin/ pressure vessels.

Corrosion due to o+idation at hi/h

temperature is called scalin/. e./. steamboilers. 6+foliation is a type of scalin/ causedby o+idation in steam atmosphere e./.feedBater heaters. Aeneral corrosion ta-esplace due to a corrosive chemical or impurityover the e+posed surface.

Inter/ranular corrosion occurs in stainlesssteels heated upto ;;?;; ;C and thene+posed to corrosive conditions.

Aalvanic corrosion happens due tocurrent HoBin/ betBeen toB dissimilarmetals Bhich form a /alvanic cell. It occursBhen tBo such metals are Doined to/ether at

a Beld. = typical pair is iron and copper.Corrosion pittin/ results fromelectrochemical potential set up bydi>erences of o+y/en concentration insideand outside the pit. The o+y/en?lean part actsas anode and the metal surface as cathode.

Mnife?line corrosion ta-es place betBeenparent and Beld metals. e./. austeniticstainless steels.

Crevice or contact corrosion occurs at thepoint of contact of a metal and non?metallicmaterial. e./. threaded Doints.

Er/si/n is a type of corrosion and iscaused by HoB restriction or chan/e of direction. e./. elboBs* tees* baJes* no##lesand valves and point opposite to inlet no##le.

34


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It is increased if the HoB contains solidparticles or by bubbles in li:uids and by tBophase HoB. ,et steam HoB* air Det Hashin/HoB and pump cavitation can cause severeerosion.

6+ternal corrosion occurs by material of

insulation. eachin/ of chloride salts frominsulation can corrode pipeBor-.9nder/round pipin/ can be corroded by

soil due to electrochemical action andcathodic protection is used to control it.

Stress c/rr/si/n cracDin7 is the resultof corrosion and static tensile stresses.Corrosion fati/ue is caused by corrosion andby alternatin/ fati/ue stresses. Chlorides area common cause of stress corrosion crac-in/.Stress may be internal or e+ternal. Stresscorrosion crac-in/ caused by an al-alinesolution is -noBn as caustic embrittlement*Bhich has been a fre:uent cause of failure in

boilers. Therefore treatment to boilerfeedBater &removal of caustic and chloridecontent' is necessary. Control measures are ?elimination of corrodants* reduction of residual stresses and vibrations etc.

In plants handlin/ nitric acid and nitrates*nitrate stress c/rr/si/n cracDin7> of mildsteel is possible. This Bas the reason of crac-in the reactor at 5li+borou/h resultin/ inremoval of the reactor and temporaryinstallation of the 2;] pipe Bhich /ave Bayand the disaster too- place.

=t hi/h stresses and temperatures* traces

of other metals li-e #inc can cause rapid andsevere 3inc em;rittlement of some types of steels. ,ettin/ of the steel by molten #inc isa favourable condition to #inc embrittlement.

This may cause local (re and catastrophicfailure. To avoid this* #inc?coated items shouldnot be placed in direct contact Bith stainlesssteel or in positions Bhere they can dripmolten #inc on it. 5or e+ample /alvanisedBire nettin/ used in insulation should not bein direct contact Bith stainless steel pipe.)urin/ Beldin/ and fabrication* #inccontamination of stainless steel should beprevented. Special metallur/ical e+amination

Bill reveal #inc embrittlement.C/rr/si/n Pre5enti/n is of hi/h

importance as it prevents accidents andreduces cost of corroded materials.Substitution of non?corrosive or less corrosivematerial &e./. SS instead of %S' tolerated bythe process technolo/y and economy andselection of such material from the desi/nand erection sta/e avoids most of thecorrosion problems. Then selection of poBdercoated metal parts &sheets* structuralmembers* machine parts* /uards* covers etc.'instead of painted* /ive lon/ life. %ild steel

parts of tan-s structures pipin/* machinesand vessels must be re/ularly painted byanti?corrosive paints. Protection from rain and

plant Bater* drippin/ and lea-in/ of corrosivechemicals* o+idation and contact of #inc andcopper is necessary. 0apid cleanin/ of spilla/e* /ood house-eepin/* cathodicprotection* control of HoB* Huctuations andvibrations* Bater softenin/ and removal of

salts* chec-in/ of scale formation on platesand tubes* thic-ness measurement anddefect monitorin/ by N)T methods stated infore/oin/ Part 7..2 and latest instrumentsand e:uipment* scannin/ by computermethods* descalin/* decho-in/* scrappin/*timely repairin/ and preventive maintenanceare also useful to avoid corrosion and erosion.

ther methods to stop corrosion anderosion are as under 8

1. TBo compatible metal prevent or sloBdoBn the rate of corrosion.

2. = strate/ically placed /as-et i.e. to provide

insulatin/ material betBeen the tBometals.

3. Cathodic protection and conversioncoatin/.

4. Crevice corrosion can be avoided bychoosin/ materials havin/ corrosionresistance. Stainless steels are prone tocrevice corrosion and not recommendedfor such use.

. )e#inci(caiton &removal of #inc from brass'can be prevented by usin/ alloys of brasscontainin/ Sn* =s* P or Sb.

!. 9se of non?metallic material li-e plastic.

$. =pplyin/ monomolecular (lm &inhibitor' of /rease* paint* synthetic or/anic coatin/ ora plastic sheet &liner' over the surface.

. 9se of o+y/en scaven/ers &e./. Sodiumsulphite and hydra#ine' to add into boilerBater to remove o+y/en.

7. Inhibitors li-e phosphonates are used incoolin/ Bater for corrosion control.

1;. 9se of acid pic-lin/ as corrosioninhibitors.11. 9se of heavy oils or /reases* Ba+es

dissolved in solvents or sulphonate saltsdissolved in petroleum as a barrierbetBeen the environment and the metal

surface."oBever it should be veri(ed thatchemicals bein/ selected as inhibitorsshould not be carcino/enic as they cancause cancer. 5or e+ample p?t?butylben#oic acid* sodium nitrite* nitrosamines*thiourea etc. are carcino/enic and shouldnot be used.

12. Non?metallic materials li-e plastic* rubberand synthetic elastomers can also beattached by corrosion or crac-in/ due tosolvent* environmental stress or thermale>ect. Corrosion process in plastic ta-es

place because of sBellin/* softenin/ or lossof physical properties. Polyurethane*polyethylene* polystyrene* =


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homopolymers and polyethersulfone arethe plastics havin/ /ood resistance a/ainstcorrosion.

0ubber linin/ &e./. chloroprene* nitrile andbutyl rubber' on steel tan- prohibits attac- of

stron/ acids.

= PR!CESS HAAR$S AN$C!NTR!S

=41 Ty9es /f Pr/cesses and!9erati/ns includin7 %nitPr/cesses@ %nit !9erati/nsand !ther Pr/cesses

Aenerally in a chemical plant processes areclassi(ed as batch processes or continuous

processes or their combination. In a batchprocess relatively more man?poBer isre:uired* the Bor-ers are e+posed to ha#ardsmore fre:uently and process automation andinstrumentation are possible only to a limitede+tent. = continuous process is carried out ina closed vessel or circuit and /oodautomation and instrumentation are possible.%any processes are operated at hi/hpressure and hi/h temperature &as in case of petroleum and petrochemical industry' forBhich automatic Barnin/* monitorin/ andcontrollin/ devices are desired. Pressure andtemperature should be properly controlled by

coolin/ and safety devices. 5lammable*e+plosives and solve

18. chapter - 18 safety in chemical industry

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