Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2014-11-05 — TX
Operator
Southern Natural Gas Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$300
Incident datetime
2014-11-05 05:15
Report number
Location
TX
Narrative
On november 5, 2014, at 5:08 am est, gas control sent a start command to initiate a start on thomaston unit 3. Trending data indicates that at 05:10 am est, during the purge/pressurize sequence, the unit vent valve failed to close and the start sequence failed. All affected valves should have returned to their normal positions. At 5:15 am est, gas control received a sequence alarm indicating unit valves were out of position; the purge valve remained open, resulting in the unintended release of gas through the vent valve. Gas control dispatched a technician to the facility. At 06:28 am est, the technician arrived on site, checked the compressor automation system and sent a 'close' command to the purge valve and it closed properly, stopping the unintended gas release. 1/21/2014 - update - faulty relay and loose wiring contributed to the failure of the vent valve to close.
Detailed record list
Report Received Date
2014-12-03 00:00:00
Iyear
2014
Report Number
20140130
Supplemental Number
16620
Report Type
Supplemental Final
Operator Id
18516
Name
Southern Natural Gas Co
Operator Street Address
1001 Louisiana St, Ste 1000 Suite 1000
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Local Datetime
2014-11-05 05:10:00
Location Latitude
32.787718
Location Longitude
-84.25427
Nrc Rpt Num
1100216
Nrc Rpt Datetime
2014-11-05 09:35:00
Commodity Released Type
Natural Gas
Unintentional Release
12000
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Shutdown Explain
Facility Continued To Operate Safely
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2014-11-05 05:15:00
On Site Datetime
2014-11-05 06:28:00
On Off Shore
Onshore
Onshore State Abbreviation
Ga
Onshore Postal Code
30256
Onshore City Name
Thomaston
Onshore County Name
Hudson
Designated Location
Milepost
Designated Name
346.954
Pipe Fac Name
Thomaston Compressor
Segment Name
Thomaston Compressor
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
Valve
Valve Type
Auxiliary Or Other Valve
Installation Year
Unknown
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Vent Valve Release
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
860
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
40620
Est Cost Intentional Release
0
Est Cost Prop Damage
300
Est Cost Emergency
200
Est Cost Other
0
Prpty
41120
Accident Psig
928
Mop Psig
1200
Mop Cfr Section
192.619(A)(1)
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Accident Identifier
Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
Gas control personnel noticed scada alarm. The controller did not contribute to the incdent.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Malfunction Of Control/relief Equipment
Eq Failure Type
Malfunction Of Control/relief Equipment
Block Valve Ind
Yes
Other Control Relief Ind
Yes
Other Control Relief Details
Auto-Operated Unit Vent Valve
Eq Additional Other Ind
Yes
Eq Additional Other Details
Latch Relay" Failed, Preventeng Vent Valve From Closing Properly
Preparer Name
Z****** R*****
Preparer Title
Engineer - Pipeline
Preparer Email
Z*************@k***********.com
Preparer Telephone
713-420-6633
Authorizer Name
Z****** R*****
Authorizer Title
Engineer - Pipeline
Authorizer Telephone
713-420-6633
Authorizer Email
Z*************@k***********.com
Narrative
On november 5, 2014, at 5:08 am est, gas control sent a start command to initiate a start on thomaston unit 3. Trending data indicates that at 05:10 am est, during the purge/pressurize sequence, the unit vent valve failed to close and the start sequence failed. All affected valves should have returned to their normal positions. At 5:15 am est, gas control received a sequence alarm indicating unit valves were out of position; the purge valve remained open, resulting in the unintended release of gas through the vent valve. Gas control dispatched a technician to the facility. At 06:28 am est, the technician arrived on site, checked the compressor automation system and sent a 'close' command to the purge valve and it closed properly, stopping the unintended gas release. 1/21/2014 - update - faulty relay and loose wiring contributed to the failure of the vent valve to close.
| Report Received Date | 2014-12-03 00:00:00 |
|---|---|
| Iyear | 2014 |
| Report Number | 20140130 |
| Supplemental Number | 16620 |
| Report Type | Supplemental Final |
| Operator Id | 18516 PHMSA Enforcement |
| Name | Southern Natural Gas Co |
| Operator Street Address | 1001 Louisiana St, Ste 1000 Suite 1000 |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77002 |
| Local Datetime | 2014-11-05 05:10:00 |
| Location Latitude | 32.787718 Google Maps OpenStreetMap |
| Location Longitude | -84.25427 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1100216 NRC Report How to search |
| Nrc Rpt Datetime | 2014-11-05 09:35:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 12000 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | No |
| Shutdown Explain | Facility Continued To Operate Safely |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2014-11-05 05:15:00 |
| On Site Datetime | 2014-11-05 06:28:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ga |
| Onshore Postal Code | 30256 |
| Onshore City Name | Thomaston |
| Onshore County Name | Hudson |
| Designated Location | Milepost |
| Designated Name | 346.954 |
| Pipe Fac Name | Thomaston Compressor |
| Segment Name | Thomaston Compressor |
| 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 | Valve |
| Valve Type | Auxiliary Or Other Valve |
| Installation Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Vent Valve Release |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 860 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 40620 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 300 |
| Est Cost Emergency | 200 |
| Est Cost Other | 0 |
| Prpty | 41120 |
| Accident Psig | 928 |
| Mop Psig | 1200 |
| 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 System |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | Yes |
| Scada Conf Ind | Yes |
| Accident Identifier | Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations) |
| Investigation Status | No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate) |
| Investigation Status Details | Gas control personnel noticed scada alarm. The controller did not contribute to the incdent. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Malfunction Of Control/relief Equipment |
| Eq Failure Type | Malfunction Of Control/relief Equipment |
| Block Valve Ind | Yes |
| Other Control Relief Ind | Yes |
| Other Control Relief Details | Auto-Operated Unit Vent Valve |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Latch Relay" Failed, Preventeng Vent Valve From Closing Properly |
| Preparer Name | Z****** R***** |
| Preparer Title | Engineer - Pipeline |
| Preparer Email | Z*************@k***********.com |
| Preparer Telephone | 713-420-6633 |
| Authorizer Name | Z****** R***** |
| Authorizer Title | Engineer - Pipeline |
| Authorizer Telephone | 713-420-6633 |
| Authorizer Email | Z*************@k***********.com |
| Narrative | On november 5, 2014, at 5:08 am est, gas control sent a start command to initiate a start on thomaston unit 3. Trending data indicates that at 05:10 am est, during the purge/pressurize sequence, the unit vent valve failed to close and the start sequence failed. All affected valves should have returned to their normal positions. At 5:15 am est, gas control received a sequence alarm indicating unit valves were out of position; the purge valve remained open, resulting in the unintended release of gas through the vent valve. Gas control dispatched a technician to the facility. At 06:28 am est, the technician arrived on site, checked the compressor automation system and sent a 'close' command to the purge valve and it closed properly, stopping the unintended gas release. 1/21/2014 - update - faulty relay and loose wiring contributed to the failure of the vent valve to close. |
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