PRESENTATION on

GAS SAFETY PRACTICES AT RINL/VSP

By S.K SWAIN, DGM(Maint.)

S.ANUJ LAKRA, AGM(O)-EMD

CH TRUPATI RAO, Mgr(BF)

RINL, Vizag Steel Plant

The 1st ISP to be certified for Quality, Health & Safety and Environment

1st Steel Plant to get ISO 50001 certification for Energy Management

1st Steel PSE to sign Integrity Pact of Transparency International

CMMI Level 3 certification for IT Systems and ISO 27001 for ISMS

1st ISP to be 5S Certified for the whole plant

Major Accreditations

BPTS

TRT

100%

Continuous

Casting

LD gas

recovery

Evaporative

Cooling CO Battery with Coke Dry Quenching and Back Pressure Turbine Station

Blast Furnace with Top Recovery Turbine and BF gas recovery

Rolling Mills with Stelmor & Tempcore (TMT) processes equipped with evaporative cooling

for waste heat utilization

Sinter cooler

heat recovery

GASES HANDLED IN VSP

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OXYGEN NITROGEN L.P.G ARGON COKE OVEN GAS BLAST FURNACE GAS L.D.CONVERTOR GAS CDCP RECIRCULATING GAS EXHAUST GASES FLUE GASES

Typical analysis of gases produced in the plant

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Constituents B.F. Gas C.O. Gas L.D. Gas

Carbon monoxide (CO) 25 % 6.4% 63 - 69%

Hydrogen (H2) 1.8 % 56.7 % 2 – 3 %

Methane (CH4) 0.4 % 27.8 % ---

Carbon Dioxide (CO2) 18.0 % 2.3 % 16.5 - 17%

Nitrogen (N2) 54.0 % 3.5 % 14.5–19.5%

Oxygen (O2) 0.5 % 0.3 – 0.5 % ---

CnHm --- 2.3 % ---

Hydrogen sulphide (H2S) --- 0.4 % ---

Naphthalene --- 0.65gm/NM3 ---

Properties of gases produced in the plant

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B.F. Gas C.O. Gas L.D. Gas

Ignition temp 600-650OC

550-600OC 600-650OC

Explosive range 45% – 70 % 7% – 30 % 20% – 70 %

Density 1.28 Kg/NM3 0.42-0.45Kg/NM3 1.30Kg/NM3

Calorific value 840 Kcal/NM3 4300 to

4500Kcal/NM3

2000 Kcal/NM3

Nature

Poisonous,

colourless,

explosive,

odourless,

burns with blue

flame, heavier

than air

Explosive,

colourless,

poisonous, typical

smell of hydrogen

sulphide and

naphthalene, burns

with yellow flame,

lighter than air

Poisonous,

colourless,

explosive,

odourless,

burns with

blue flame,

heavier than

air

BY PRODUCT FUEL GASES GENERATION

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GASES

Generation

Vol in Lakh

(Nm3/hr)

Network Pr

( MMWC)

Approx.Length

( KM )

Dia in (MM)

BFG

11.5-12.0

1200 - 1300

16

150 - 3500

COG

1.5 – 1.6

700 –

800(Suc)

1300 – 1500

(Del)

22

50 - 2000

LDG

0.6 – 0.7

1300 – 1400

03

1500 - 2000

Why Handling of gases so hazardous?

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Most of the gases have no color, odour or taste

Easily disperses/spreads in environment (unlike solids or liquids).

All gases are hazardous except normal air

Difficult to be detected by human senses

Entry through respiratory route

GAS HAZARDS

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Suffocation (Simple asphyxia)

Gas poisoning Fire

Explosion

Suffocation/Asphyxia

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Lack of oxygen in respiration system Oxygen depletion by - Displacement - Consumption One/Two deep breath of N2 can be fatal In USA from 1992 to 2002, 80 persons killed , 50 injured

in 85 nos. nitrogen incidents. Confined space entry permit Monitoring of oxygen by portable monitors Control of re entering hazardous materials

Safe Working Practices for Fuel Gas line isolation

1. Closing of Upstream valve

2. Filling of downstream U Seal 3. Purging of downstream of U Seal

4. Ensure Zero PPM and Zero Pressure

5. Blanking of Downstream of U-seal flange

6. Where there is no U-seal , water fill DDGV.

U Seal

Safe Working Practices for

fuel Gas line charging

(1) Purging the line with N2 for below 1% Oxygen

/ Steam till profuse steam is visible from end

bleeder.

(2) Break the U-Seal & open the Isolation Valve

(3) Close Purge media & vents.

(4) Check all joints for CO .

(5) Rectify the leakage (if any) with gas safety

precautions..

Best Maintenance Practices

wrt Fuel Gas line

(1) Provision of U Seals as an additional Isolation

(2) Substitution of NRS Gate valves by RSGV

(3) Substitution of GTI by RS Gate valves

(4) Installation of more Nos. of Goggle valves

(5) Maximum Usage of Flanged end valves and Compensators.( Inter-

changability, less inventory)

(6) Provision for vertical blanking / deblanking facilities on Horizontal

Mains.

(7) Fire hydrant all along the pipelines

(8) Nitrogen Injection Facilities along the pipeline throughout the

plant.

(9) Water filling in double disc gate valve.

(10) PPM of all critical valves once in 3 months.

Best Practices wrt

Blanking / Deblaking on Fuel gas line

(1) Completion of all preparatory jobs like bolts

revision , Rings , gaskets preparations etc in

advance.

(2) Monitoring of downstream pressure for

assessment of valve passage.

(3) Filling of U seals and Blanking on the

downstream Flange as well as drain valve.

(4) Purging the line with Nitrogen

(5) Sequence of jobs as per SOP/ SMP.

(6) Ensure Zero gas job.

Best Practices wrt

Blanking /De-blanking on Fuel gas line

(1)Duly signed protocol

(2)Stand by fire tender

(3)Continuous monitoring by gas safety

(4)Usage of breathing apparatus

(5)No smoking / no naked fire in the vicinity

(6) No break in between the job

(7) Executed preferably during day light hours

(8) No during Thundering / Lightening

(9) Grease coated tools

(10) Proper platform / escape routes

Best maintenance Practices on Live Fuel gas line

(1) NDT of defective area

(2) Injection of Nitrogen from the upstream to dilute

the CO & Explosive

(3) Monitor for variation in CV of consumers.

(4) Application of cold weld compound

(5) Cover the flanges , valves with Non asbestos

clothes during hot jobs.

(6) Jacketing / Padding ( Weld with low current)

Blast Furnace Gas Net Work

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COG NET WORK

13

Safety measures followed at RINL

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1. All the gas jobs are carried out strictly with protocols signed by the competent authority

2. The total gas net work is inspected periodically to assess the leakages 3. The leakages on gas lines are arrested immediately by plugging and

subsequently by padding the gas lines. 4. Healthiness of the pipe line is checked by NDT ( Ultrasonic measuring

instrument) every year 5. The standard protocols are prepared and are used for all the repetitive

jobs 6. All the safety inter locks are checked periodically 7. All the UPS for the critical equipments are checked periodically 8. All the Nitrogen injection facilities to gas lines are checked for

mitigating the any eventuality 9. L D gas holder internal inspection is carried out annually to assess the

condition of gas holder seal and piston

GAS SAFETY TRAINING METHODOLOGY

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1. Gas safety training is given to all the new entrants to the department before assigning the tasks.

2. Gas safety training classes are conducted at T& DC regularly to cover all the employees (Executives and Nonexecutives) of the plant

3. All the contract staff reporting EMD are provided with gas safety training on the 1st day of reporting

4. All the contract staff reporting in the other departments but working near gas lines are also provided gas safety training

5. Mock drill are conducted periodically to access the readiness of various sections to fight the eventuality

INSTALLATION OF SERIES DRIP POTS

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INSTALLATION OF SERIES DRIP POTS

17

Major incidents in V.S.P.

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Suffocation in CDCP chamber -- Oct ’89 Collapse of BF network to gets -- Apr ’92 Explosion during mixer light up -- Jul ’92 Gas leakage at GMS-1 -- Jun ‘93 Gas poisoning during GTI operation (at GRP) -- Sep ‘95 Launder cleaning at converter -- Sep ’95 Ingress of air into Gas holder -- Sep ’95 Explosion of BF gas line at TPP -- Apr ’06 Gas poisoning due to failure of nitrogen (at GRP) – Apr ’08 Fatal accident in benzol tank -21/7/2009 Gas poisoning due to COG leakage(CCD) – 9/11/2009 LPG & O2 Cylinders explosion at pro.area -- 12/01/2010 Fatal incident at oxy.pr.reducing stn-2 -- 13/06/2012 Gas poisoning in TPP MCR -- 21/01/2013

Key steps in maintenance of gas lines/equipment

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a) Isolation

b) Purging

c) Ventilation

d) Analysis

Challenges during Common Shutdown

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• Unique concept in RINL • Around 6.3 kms of BF gas network put down • Isolating all the consumers • Venting the huge amount of BF gas safely • Purging the entire BF Gas network with Nitrogen(

around 1,00,000 nm3/hr intermittently) • Analysis at a number of points for CO & Explosive

mixture • Close coordination with all the consumers and various

agencies • Leak test & normalisation Common shutdown.pdf

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GAS SAFETY PRACTICES

Gas Safety Best Practices • All jobs are done with Protocol

• Gas safety talk before start of job

• Gas Jobs are restricted to day light hours.

• Strict compliance of Confine Space

permit(150)

• HWP is must for all hot works

• RAL is brought to 4 for each activity.

• Hierarchy of Control

• E – S – Ec - Ac - PPE

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• Monthly Mock drill on various themes like Gas poisoning , Fire on Gas Lines etc.

• Installation of Online CO Monitor in critical area across the plant and monitoring through PLC.

• Distribution of portable CO Monitor to all the gas consuming departments.

• Availability of gas mask in all the control Rooms of gas consuming departments.

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Gas Safety Best Practices

Gas safety appliances available

1. Closed circuit SCBA

i) Travox-120[120 Min]

ii) Oxy SR – 45 [45 Min]

iii) P-30 Gas mask 4 hrs]

iv) P- 30 Ex[4 hrs]

v) Fenzy [ 2 hrs]

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Gas safety appliances available

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2. Open circuit ( Comp air breathing apparatus)

i) Scott air mask [ 60 Min]

ii) RN/BN air mask[ 30 Min]

3. Detectors:

i) CO & Oxygen monitors

ii) Explosive meters

4. Portable automatic ventilator

(Pneu pac Artificial respirator)

Gas Safety facilities • In house calibration of CO Monitors every 180 days.

Bulk message calibration alert facility to owners.

• In house Testing of SCBA every 90 days or

immediately after use.

• Exclusive gas safety van equiped with( 4 SCBA + 1

Artificial Respirator ) .

• Oxygen cylinder (Gas masks) filling facility up to 220

bar/330 bar( 02 Nos Draggr U300DS)

• High pressure air compressor for filling of compressed

air cylinders up to 330 bar( 2 Nos. Coltri Std , Ergo )

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Future Plans for Network safety and Maintenance

Installation of U-seal on BFG Line for I&S Zone.

Installation of U-seal between BF1 &2

Provision for second COG Flare stack along with COB-5

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Thank you

राष्ट्रीय इस्पात निगम लिलमटेड RASHTRIYA ISPAT NIGAM LIMITED