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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
5
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
6
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
7
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
8
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?
9
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
10
Suffocation (Simple asphyxia)
Gas poisoning Fire
Explosion
Suffocation/Asphyxia
11
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
12
COG NET WORK
13
Safety measures followed at RINL
14
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
15
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
16
INSTALLATION OF SERIES DRIP POTS
17
Major incidents in V.S.P.
18
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
20
a) Isolation
b) Purging
c) Ventilation
d) Analysis
Challenges during Common Shutdown
21
• 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
22
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
23
• 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.
24
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]
25
Gas safety appliances available
26
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 )
27
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
28
Thank you
राष्ट्रीय इस्पात निगम लिलमटेड RASHTRIYA ISPAT NIGAM LIMITED