GAS LINE MAINTENANCE &

SAFETY PRACTICES IN

BOKARO STEEL PLANT

PRESENTED BY:

VINOD KUMAR

MANAGER

ENERGY MANAGEMENT DEPARTMENT

BOKARO STEEL PLANT

BOKARO STEEL PLANTBF, CO & CONV. GAS NETWORK

IMF

69144

RRS

85

FORGESHOP

M/CSHOP

STRL.SHOP

ICF

STEELFDY

126

126/40

144/9

144/40

LRSII

43/11

4/37 SMS-II CCDMIXER

RSRS

SMS I

MIXER

GH-2

GH-143/28

30

65/11

65/42

GMBS

158172 186

HSM

195

202

CRM

DSURRHS

202/12

202/15

195/7RGBS

222

234 253

HCl

HRCF

26/2424

43/45

BMS

IMY

SL. MILL

158/63

202/14

PGP

GAS LINES IN BSL

We at Bokaro Steel Plant to follow the basics:

• DESIGN IT RIGHT

• OPERATE IT RIGHT AND,

• MAINTAIN IT RIGHT

Safety by Design in Existing Gas Lines

• Russian Design as per GOST Codes, Standards and Specification

• There are no explosion flaps in the ODPL network• Expansion joints are provided to take up a maximum

compensation of 40mm per compensator• Condensate drain points are provided at regular interval

to take up the load of condensate from the gas line• Purging points and bleeders are designed for steam

(media) Contd.

Safety by Design in Existing Gas Lines

• For large dia. Pipelines, supports are designed with high factor of safety (four legged rigid and two legged swinging type flexible supports)

• Smaller dia. pipelines (up to 1000mm) have sliding / rolling type flexible supports

• Slope of the gas lines is maintained at a rate 5mm per meter.

• All the branch lines emerging out of main gas line are provided with rising stem type gate valves as isolation valves.

Contd.

Safety by Design in Existing Gas Lines

Limitations • All the branch lines emerging out of main gas line are

provided with rising stem type gate valves as isolation valves. No provision of U seals for quick & safe isolation of Branch lines.

• No provision for partial isolation of main gas network

• No alternate gas line• No provision of continuous online CO monitoring

facility at potential hazard area.• No provision of gas holders for BF & CO gas.

Improvement in Original Design

• Action initiated to include provision of Water U-seals at strategic places for isolation purpose.

• Provision of U seals has been included in all the upcoming gas lines under modernization.

• Continuous online CO monitoring facilities has been installed at potential hazard area.

• Provision of Nitrogen purging has been introduced at many places. ( 5 locations)

The individual components of Gas line system are

• Pipe• Piping fittings• Valves• Expansion joints• Bolts and gaskets (fasteners and sealing)• Accessories such as bleeders, purging

points, Drains, pipe supports etc.

Safety of Gas lines by Maintenance Practices

Good, effective and safe maintenance of the gas lines can be ensured by:

• Proper understanding of the design of gas lines and its equipments

• Proper understanding of the Gas safety aspects involved in the job each time

• Use of the latest applicable codes/ standards like IPSS, IS, ASME, etc.

Safety of Gas lines by Maintenance Practices

Maintenance practices for gas lines is can be divided into two categories:

• Preventive (both in charged and isolated conditions) and,

• Corrective (both in charged and isolated conditions

Safety of Gas lines by Maintenance Practices

Preventive maintenance practices in BSL include:

• Schedule maintenance of gas line equipments with emphasis on keeping Drain pots in healthy condition

• Thickness measurement of gas lines at identified critical locations

• Cladding of the gas lines and painting

Safety of Gas lines by Maintenance Practices

Corrective maintenance practices in BSL include:

• Regular leakage detection, corrosion detection & control, of critical areas

• Twice a year, members of a dedicated task force walk every foot of the pipeline –with digital CO monitor which can detect extremely low concentrations (Parts Per Million) and to look for physical condition of the pipeline and the structures.

Safety of Gas lines by Maintenance Practices

• Immediate control of gas leakage by temporary means like clamping, cold welding with steel putty or M-seal etc.

• Permanent repair of the defect either by welding or replacement of the part as the case may be

• Proper Gas Safety protocol is followed for every case irrespective of method of rectification (online or isolated condition)

Safety of Gas lines by Maintenance Practices

Effective and extensive use of gas safety tools/ equipment like:

• Closed circuit self contained Oxygen Breathing apparatus (Gas masks)

• Artificial Breathing Apparatus (ABA)• Fresh Air Breathing Apparatus (FABA)• Compressed Air Breathing Apparatus (CABA)• Digital CO detector• Explosimeter• Oxygen Analyzer etc.

in both preventive and corrective maintenance practices

Safety of Gas Lines by Operational Practices

At BSL some of the operational measures adopted towards safety of gas lines include:

• Adhering to SOPs

• On-line monitoring and control of gas net work pressure and flow round the clock.

• Control room operators are highly skilled at responding to emergency situations

Safety of Gas Lines by Operational Practices

The massive task of safe handling of the gases

can be gauged from Production of gases in BSL

• BF Gas -1000x103 Nm3/hr

• CO Gas - 125-130x103 Nm3/hr

• LD Gas - 10-12x103 Nm3/hr (this is being flared currently)

Safety of Gas Lines by Operational Practices

Network pressure maintained by Gas Control through :

• Diverting / Reducing gas to Buffer Consumer (Power plant)

• In extreme cases, Pressure is maintained by • Releasing Surplus gas through Flare stacks / bleeders.

– BF Gas - 2 x 120000 Nm3/hr. – CO Gas - 2 x 30000 Nm3/hr.

• Restricting gas to the low priority customers in case of shortage.

Safety of Gas Lines by Operational Practices

Process Safety Management is further ensured by:

• Training programs for the new staff

• Refresher courses for the existing staff

• Checking of safety interlocks as per schedule

• Mock drills for emergency situations like Power Failure, Gas Leakage etc.

SAFETY RELATED INCIDENT – A CASE STUDY OF NEAR MISS

Job Description: Cladding of a leaking double disc compensator

installed in the BF gas line of Dia. 3000mm

The Job involved cutting & welding and had to be carried out online as it was on main gas network which cannot be shut down

Challenges:• A Coke Oven Gas Gland Compensator just below

this BF gas compensator at a gap of about 1.5m • The CO concentration on the working platform was

more than 1500PPM• The height of the gas line 14m and large pipe dia.

SAFETY RELATED INCIDENT

Potential Hazards in the job;• Gas Exposure hazard• Fire hazard• Explosion Hazard• Working Height Hazard

All the related risks were considered and a proper protocol was prepared to carry out the job safely

SAFETY RELATED INCIDENTAs per Plan• Two welders to work from both side of Gas line.

• One supervisor to supervise the job.

As per protocol• No additional worker was allowed on working platform

• Arrangement to use Compressed air masks by all three.

• Arrangement of Standby fire tender.

• Arrangement of Rescue Van equipped with all accessories at site.

• Two air blowers from both side to disperse gas from platform.

• Arrangement of running steam hose on either side.

SAFETY RELATED INCIDENT

The incident

• Supervisor noticed that one welder on opposite side had stopped welding.

• Supervisor tried to contact by shouting.

• No response from welder.

• Supervisor immediately crossed over the Gas line.

• The welder found talking on mobile phone without mask.

SAFETY RELATED INCIDENT Action taken• The welder was immediately instructed to wear the

mask and leave the job.• The welder got down the stairs on his own along with

the supervisor and was apparently appearing to be normal.

• However, as a precautionary measure he was given Oxygen with the help of Artificial Breathing Apparatus

Though the incident did not result in any kind of gas exposure to the welder due to alertness of supervisor but this could have been serious.

THANK YOU