GTG incident on 2013-03-20 — MI

Operator
Viking Gas Transmission Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$100
Incident datetime
2013-03-20 06:29
Report number
Location
MI
Narrative
An original equipment manufacturer (oem) fitting on a 4x6 anderson-greenwood relief valve located on a reciprocating natural gas compressor discharge piping, failed on march 20, 2013 at the ada, mn compressor station, causing the unintended release of natural gas. Employees from the ada compressor station were notified of the blowing gas at approximately 6:29 a.M. By a neighbor to the compressor station. The responding employees were able to identify the problem and shut down the unit and the venting gas by 7:02 a.M. A review of the station controller log at the ada compressor station indicated that the oem fitting failed at 00:17 a.M., which allowed gas to vent for 6 hours and 45 minutes. The event was reported to the nrc in anticipation of gas loss exceeding the 3,000 mcf threshold level. A new fitting was installed to replace the failed fitting and the compressor was restored to normal service the same day. The failed fitting was sent to sherry labs for a failure analysis. The failures analysis concluded the relief valve fitting fractured through the 1/2" diameter threads of one end by uniaxial bending fatigue. The primary cause of failure appreared to be use of a material with insufficient fatigue resistant for the application. The failed fitting was a oem standard supplied fitting, which is part of the pilot sensing system. The oem has designed a new high strength, stainless steel component which will replace those existing pilots with similar relief pilot installations. This work will be completed in 2013. Over-pressure was not a contributing factor to the fitting failure.
Detailed record list
Report Received Date
2013-04-17 00:00:00
Iyear
2013
Report Number
20130035
Supplemental Number
16768
Report Type
Supplemental Final
Operator Id
Name
Viking Gas Transmission Co
Operator Street Address
500 Woodward Ave Suite 2900
Operator City Name
Detroit
Operator State Abbreviation
MI
Operator Postal Code
48226
Local Datetime
2013-03-20 00:17:00
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2013-03-20 08:00:00
Commodity Released Type
Natural Gas
Unintentional Release
44059
Intentional Release
30
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Shutdown Explain
Unit #1a Was Shutdown But Other Compression Remained Online.
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2013-03-20 06:29:00
On Site Datetime
2013-03-20 06:43:00
On Off Shore
Onshore
Onshore State Abbreviation
Mn
Onshore Postal Code
56510
Onshore City Name
Ada
Onshore County Name
Norman
Designated Location
Milepost
Designated Name
Mp2207-1+0.0
Pipe Fac Name
Ada Compressor Station
Segment Name
Mp2207-1+0.0
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Compressor Station Equipment And Piping
Item Involved
Other
Item Involved Details
Relief Valve Pilot Sensing Line Fitting
Installation Year
1967
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
315
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
189674
Est Cost Intentional Release
0
Est Cost Prop Damage
100
Est Cost Emergency
100
Est Cost Other
0
Prpty
189874
Accident Psig
816
Mop Psig
877
Mop Cfr Section
192.619(A)(1)
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Pipeline Function
Transmission In Storage Field
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Notification From Public
Investigation Status
Yes, specify investigation result(s): (select all that apply)
Invest Incorrect Action Ind
Yes
Employee Drug Test Ind
Yes
Contractor Drug Test Ind
No
Num Employees Tested
1
Num Employees Failed
0
Cause
Equipment Failure
Cause Details
Threaded Connection/coupling Failure
Eq Failure Type
Threaded Connection/coupling Failure
Other Stripped Ind
Other
Other Stripped Details
1/2" Threaded Connection On Oem Steel Cross Fitting For Relief Valve Pilot Sensing Line
Additional Defect Ind
Yes
Eq Additional Other Ind
Yes
Eq Additional Other Details
See Attached Failure Analysis Report From Sherry Labs
Preparer Name
P** V******
Preparer Title
Manager Regulatory Compliance - Dot
Preparer Email
P**********@o****.com
Preparer Telephone
918-588-7734
Preparer Fax
918-591-5032
Authorizer Name
W** D*****
Authorizer Title
Vp Natural Gas Pipeline Operations
Authorizer Telephone
918-588-7414
Authorizer Email
W*********@o****.com
Narrative
An original equipment manufacturer (oem) fitting on a 4x6 anderson-greenwood relief valve located on a reciprocating natural gas compressor discharge piping, failed on march 20, 2013 at the ada, mn compressor station, causing the unintended release of natural gas. Employees from the ada compressor station were notified of the blowing gas at approximately 6:29 a.M. By a neighbor to the compressor station. The responding employees were able to identify the problem and shut down the unit and the venting gas by 7:02 a.M. A review of the station controller log at the ada compressor station indicated that the oem fitting failed at 00:17 a.M., which allowed gas to vent for 6 hours and 45 minutes. The event was reported to the nrc in anticipation of gas loss exceeding the 3,000 mcf threshold level. A new fitting was installed to replace the failed fitting and the compressor was restored to normal service the same day. The failed fitting was sent to sherry labs for a failure analysis. The failures analysis concluded the relief valve fitting fractured through the 1/2" diameter threads of one end by uniaxial bending fatigue. The primary cause of failure appreared to be use of a material with insufficient fatigue resistant for the application. The failed fitting was a oem standard supplied fitting, which is part of the pilot sensing system. The oem has designed a new high strength, stainless steel component which will replace those existing pilots with similar relief pilot installations. This work will be completed in 2013. Over-pressure was not a contributing factor to the fitting failure.
Report Received Date 2013-04-17 00:00:00
Iyear 2013
Report Number 20130035
Supplemental Number 16768
Report Type Supplemental Final
Operator Id 21252 PHMSA Enforcement
Name Viking Gas Transmission Co
Operator Street Address 500 Woodward Ave Suite 2900
Operator City Name Detroit
Operator State Abbreviation MI
Operator Postal Code 48226
Local Datetime 2013-03-20 00:17:00
Location Latitude 47.23929 Google Maps OpenStreetMap
Location Longitude -96.52427 Google Maps OpenStreetMap
Nrc Rpt Num 1041585 NRC Report How to search
Nrc Rpt Datetime 2013-03-20 08:00:00
Commodity Released Type Natural Gas
Unintentional Release 44059
Intentional Release 30
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind No
Shutdown Explain Unit #1a Was Shutdown But Other Compression Remained Online.
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2013-03-20 06:29:00
On Site Datetime 2013-03-20 06:43:00
On Off Shore Onshore
Onshore State Abbreviation Mn
Onshore Postal Code 56510
Onshore City Name Ada
Onshore County Name Norman
Designated Location Milepost
Designated Name Mp2207-1+0.0
Pipe Fac Name Ada Compressor Station
Segment Name Mp2207-1+0.0
Federal No
Location Type Operator-Controlled Property
Incident Area Type Aboveground
Incident Area Subtype Typical Aboveground Facility Piping Or Appurtenance
Crossing No
Pipe Facility Type Interstate
System Part Involved Onshore Compressor Station Equipment And Piping
Item Involved Other
Item Involved Details Relief Valve Pilot Sensing Line Fitting
Installation Year 1967
Material Involved Carbon Steel
Release Type Leak
Leak Type Crack
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 315
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 189674
Est Cost Intentional Release 0
Est Cost Prop Damage 100
Est Cost Emergency 100
Est Cost Other 0
Prpty 189874
Accident Psig 816
Mop Psig 877
Mop Cfr Section 192.619(A)(1) View CFR 49 §192
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Pipeline Function Transmission In Storage Field
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind No
Scada Conf Ind No
Accident Identifier Notification From Public
Investigation Status Yes, specify investigation result(s): (select all that apply)
Invest Incorrect Action Ind Yes
Employee Drug Test Ind Yes
Contractor Drug Test Ind No
Num Employees Tested 1
Num Employees Failed 0
Cause Equipment Failure
Cause Details Threaded Connection/coupling Failure
Eq Failure Type Threaded Connection/coupling Failure
Other Stripped Ind Other
Other Stripped Details 1/2" Threaded Connection On Oem Steel Cross Fitting For Relief Valve Pilot Sensing Line
Additional Defect Ind Yes
Eq Additional Other Ind Yes
Eq Additional Other Details See Attached Failure Analysis Report From Sherry Labs
Preparer Name P** V******
Preparer Title Manager Regulatory Compliance - Dot
Preparer Email P**********@o****.com
Preparer Telephone 918-588-7734
Preparer Fax 918-591-5032
Authorizer Name W** D*****
Authorizer Title Vp Natural Gas Pipeline Operations
Authorizer Telephone 918-588-7414
Authorizer Email W*********@o****.com
Narrative An original equipment manufacturer (oem) fitting on a 4x6 anderson-greenwood relief valve located on a reciprocating natural gas compressor discharge piping, failed on march 20, 2013 at the ada, mn compressor station, causing the unintended release of natural gas. Employees from the ada compressor station were notified of the blowing gas at approximately 6:29 a.M. By a neighbor to the compressor station. The responding employees were able to identify the problem and shut down the unit and the venting gas by 7:02 a.M. A review of the station controller log at the ada compressor station indicated that the oem fitting failed at 00:17 a.M., which allowed gas to vent for 6 hours and 45 minutes. The event was reported to the nrc in anticipation of gas loss exceeding the 3,000 mcf threshold level. A new fitting was installed to replace the failed fitting and the compressor was restored to normal service the same day. The failed fitting was sent to sherry labs for a failure analysis. The failures analysis concluded the relief valve fitting fractured through the 1/2" diameter threads of one end by uniaxial bending fatigue. The primary cause of failure appreared to be use of a material with insufficient fatigue resistant for the application. The failed fitting was a oem standard supplied fitting, which is part of the pilot sensing system. The oem has designed a new high strength, stainless steel component which will replace those existing pilots with similar relief pilot installations. This work will be completed in 2013. Over-pressure was not a contributing factor to the fitting failure.

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