Landesumweltamt Nordrhein–Westfalen
Pipeline Accident in
North Rhine-Westphalia,
Germany
Dr. Norbert Wiese
Tel. 0201/7995-1940, Fax. -1910
[email protected]
www.lua.nrw.de
UNECE Workshop on the Prevention of Accidents of Gas Transmission
Pipelines, 8-9 March 2006, The Hague
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigations
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigations
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Pipeline Data
•
ethylene gas transmission
•
DN 300 (Da = 316 mm, s = 7 mm)
•
date of construction: 1939
•
pN = 20 bar; pop = 17 bar
•
material: analogical St 35
•
1,5 m underground
•
Regulation:
German Ordinance on High Gas Pressure Pipelines
(Gashochdruckleitungsverordnung)
German Ordinance on Long-Distance Pipelines
(Rohrfernleitungsverordnung)
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Pipeline Data
•
ethylene gas transmission
•
DN 300 (Da = 316 mm, s = 7 mm)
•
date of construction: 1939
•
pN = 20 bar; pop = 17 bar
•
material: analogical St 35
•
1,5 m underground
•
Regulation:
German Ordinance on High Gas Pressure Pipelines
(Gashochdruckleitungsverordnung)
German Ordinance on Long-Distance Pipelines
(Rohrfernleitungsverordnung)
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Pipeline Data
Requirements:
•
impermeable and resistant to expected strain
•
resistant to damage caused by mining activities
•
protection against external influences and corrosion
•
safety devices for protection against inadmissible increase of pressure
•
monitoring and recording operating pressures
•
recording loss of gas
•
limiting release of gas
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigations
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
The accident and it´s consequences
03.03.2006:
• 14:00 h: leak and release of ethylene gas  cloud
• residents  fire brigade
• simultaneous:
significant decrease of pressure  shut-down of sluice valves
• no ignition
• 15:30 h: release stopped
• 50 persons in the neighbourhood affected
• split, not cracked open completely
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigations
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Measures taken after the accident
• 6 persons evacuated
• roads within a radius of 500 m closed
• purged with nitrogen  no ignition hazard
• maximum strain estimated
• stretching devices excavated
• relief cuts set
• sleeve sockets welded
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigations
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Findings of investigations
•
rupture without macroscopic deformation
 brittle fracture
•
split of 11 mm
•
50% of perimeter
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Findings of investigations
• hook connector enlarged
• coarse-grain inside the welded
seam
• finest cuts on surface of welding
deposit
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Findings of investigations
• rupture in coarse-grain zone near heat
affected zone
• coarse-grain development and local
increase of hardness
• no relevant corrosion
• no indication to any enlarging due to inadmissible increase of pressure
• inconspicuous measurement of wall thickness
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Findings of investigations
• regular plant management and maintenance
• no necessity of mining safety measures due to previous informations
– no specified mining region
– less number of stretching devices
• hook connector accordant state of the art (1939)
But:
distinctly measurable bending and axial tensions
outside the region of damage
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Contents
• The pipeline
• The accident and it´s consequences
• Measures taken after the accident
• Findings of investigagtions
• Conclusions and initiated actions
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Conclusions
• no inadmissible increase of pressure
Cause ?
• material sufficient resistant without any indications to deterioration
spontaneous failure due to forces from outside the pipeline
– damage done by mining?
– geotectonics?
– .....?
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Initiated actions
• setting of further relief cuts
• welding of sleeve sockets for relief
– Pipeline without tension
• setting of resistance strain gauges
• Check-up of distances of stretching devices
• geodetic measurements
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Conclusions and initiated actions
Question:
If former mining activities cannot be excluded definitely:
Is it necessary to take hazards from mining
activities into account in any case irrespective of
specified former mining region or not?
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions
Thank you for
your attention !
Dr. Norbert Wiese, Department: Plant Safety, Information Systems on Plants, Substances and Emissions