Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2014-11-22 — CA
Operator
Pacific Gas & Electric Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$5,000
Incident datetime
2014-11-22 16:52
Report number
Location
CA
Narrative
On november 22, 2014 at 1652 hours an 8-inch pressure relief valve on pg&e's 34-inch transmission line l-300b at pressure limiting station 4-pls malfunctioned resulting in an unintentional release of natural gas to the atmosphere. Pg&e personnel arrived on scene at 1741 hours and the release of gas was stopped at 1948 hours by closing two bridal valves, which isolated the relief valve, allowing gas to bypass the relief valve through a mainline valve on the transmission line. No customers experienced gas service interruption. There were no injuries, no fatalities and no ignition as a result of this incident. A local residential clubhouse was evacuated by the fire department out of an abundance of caution. Local media was on scene during the incident. The pressure relief valve (prv) instrumentation tubing was replaced, its set points were re-tested, and a functional check out was completed by december 10, 2014. Prior to repairing the malfunctioning prv, overpressure protection was provided by controlling and restricting the natural gas pressure through 3-pls (the pressure limiting station upstream of 4-pls.) following the incident, pg&e contracted a third party engineering firm to perform a root cause analysis and provide recommendations to the station. Pg&e implemented several modifications and is currently in the design phase to rebuild pls-4. Pg&e inspects and calibrates pressure relief valves (prv) as part of pg&e's routine maintenance program, which is designed to ensure the reliable operation of this equipment at pg&e's pressure limiting stations. The unintentional release of natural gas is estimated to be approximately 119 million cubic feet (mmcf), therefore the incident was reported to the DOT and cpuc.
Detailed record list
Report Received Date
2014-12-22 00:00:00
Iyear
2014
Report Number
20140148
Supplemental Number
16896
Report Type
Supplemental Final
Operator Id
15007
Name
Pacific Gas & Electric Co
Operator Street Address
6121 Bollinger Canyon Rd.
Operator City Name
San Ramon
Operator State Abbreviation
CA
Operator Postal Code
94583
Local Datetime
2014-11-22 16:52:00
Location Latitude
35.160338
Location Longitude
-118.80415
Nrc Rpt Num
1103815
Nrc Rpt Datetime
2014-12-18 14:17:00
Commodity Released Type
Natural Gas
Unintentional Release
119000
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Shutdown Explain
The Relief Valve Was Isolated But This Did Not Shut Down The Pipeline
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
100
Incident Identified Datetime
2014-11-22 16:52:00
On Site Datetime
2014-11-22 17:41:00
On Off Shore
Onshore
Onshore State Abbreviation
Ca
Onshore Postal Code
93203
Onshore City Name
Arvin
Onshore County Name
Kern County
Designated Location
Milepost
Designated Name
4-Pls
Pipe Fac Name
L-300b
Segment Name
Mp 256.64
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
Intrastate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Valve
Valve Type
Relief Valve
Installation Year
2014
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Pressure Relief Valve Unintentionally Vented Natural Gas
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
650
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
564525
Est Cost Intentional Release
0
Est Cost Prop Damage
5000
Est Cost Emergency
0
Est Cost Other
0
Prpty
569525
Accident Psig
764
Mop Psig
803
Mop Cfr Section
192.619(A)(1)
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Manual
Length Segment Isolated
26
Internal Inspection Ind
No
Unsuitable Mainline Ind
Yes
Other Inspection Ind
Yes
Internal Inspection Details
A Pig Launcher Is Installed At Pls-4, Which Allows Inspection On L-300b Between Mp 256.65-298.96 (Pls-4 To Pls-5). However, The Section Of L-300b South Of Pls-4 Is Not Currently Piggable Due To Lack Of A Launcher/receiver And Plug Valves Requiring Replacement.
Operation Complications Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
Yes
Accident Identifier
Notification From Emergency Responder
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
Release of gas was due to a malfunctioned pressure relief valve and not due to the controller or control room issues
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
Relief Valve Ind
Yes
Eq Additional Other Ind
Yes
Eq Additional Other Details
Still Under Investigation
Preparer Name
C***** D****
Preparer Title
Compliance Engineer
Preparer Email
C***@p**.com
Preparer Telephone
925-328-5721
Authorizer Name
L**** D*******
Authorizer Title
Manager Of Gas Operations Regulatory Compliance
Authorizer Telephone
925-328-5756
Authorizer Email
L***@p**.com
Narrative
On november 22, 2014 at 1652 hours an 8-inch pressure relief valve on pg&e's 34-inch transmission line l-300b at pressure limiting station 4-pls malfunctioned resulting in an unintentional release of natural gas to the atmosphere. Pg&e personnel arrived on scene at 1741 hours and the release of gas was stopped at 1948 hours by closing two bridal valves, which isolated the relief valve, allowing gas to bypass the relief valve through a mainline valve on the transmission line. No customers experienced gas service interruption. There were no injuries, no fatalities and no ignition as a result of this incident. A local residential clubhouse was evacuated by the fire department out of an abundance of caution. Local media was on scene during the incident. The pressure relief valve (prv) instrumentation tubing was replaced, its set points were re-tested, and a functional check out was completed by december 10, 2014. Prior to repairing the malfunctioning prv, overpressure protection was provided by controlling and restricting the natural gas pressure through 3-pls (the pressure limiting station upstream of 4-pls.) following the incident, pg&e contracted a third party engineering firm to perform a root cause analysis and provide recommendations to the station. Pg&e implemented several modifications and is currently in the design phase to rebuild pls-4. Pg&e inspects and calibrates pressure relief valves (prv) as part of pg&e's routine maintenance program, which is designed to ensure the reliable operation of this equipment at pg&e's pressure limiting stations. The unintentional release of natural gas is estimated to be approximately 119 million cubic feet (mmcf), therefore the incident was reported to the DOT and cpuc.
| Report Received Date | 2014-12-22 00:00:00 |
|---|---|
| Iyear | 2014 |
| Report Number | 20140148 |
| Supplemental Number | 16896 |
| Report Type | Supplemental Final |
| Operator Id | 15007 PHMSA Enforcement |
| Name | Pacific Gas & Electric Co |
| Operator Street Address | 6121 Bollinger Canyon Rd. |
| Operator City Name | San Ramon |
| Operator State Abbreviation | CA |
| Operator Postal Code | 94583 |
| Local Datetime | 2014-11-22 16:52:00 |
| Location Latitude | 35.160338 Google Maps OpenStreetMap |
| Location Longitude | -118.80415 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1103815 NRC Report How to search |
| Nrc Rpt Datetime | 2014-12-18 14:17:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 119000 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | No |
| Shutdown Explain | The Relief Valve Was Isolated But This Did Not Shut Down The Pipeline |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 100 |
| Incident Identified Datetime | 2014-11-22 16:52:00 |
| On Site Datetime | 2014-11-22 17:41:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ca |
| Onshore Postal Code | 93203 |
| Onshore City Name | Arvin |
| Onshore County Name | Kern County |
| Designated Location | Milepost |
| Designated Name | 4-Pls |
| Pipe Fac Name | L-300b |
| Segment Name | Mp 256.64 |
| 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 | Intrastate |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| Item Involved | Valve |
| Valve Type | Relief Valve |
| Installation Year | 2014 |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Pressure Relief Valve Unintentionally Vented Natural Gas |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 650 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 564525 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 5000 |
| Est Cost Emergency | 0 |
| Est Cost Other | 0 |
| Prpty | 569525 |
| Accident Psig | 764 |
| Mop Psig | 803 |
| Mop Cfr Section | 192.619(A)(1) View CFR 49 §192 |
| Accident Pressure | Pressure Did Not Exceed Maop |
| Pressure Restriction Ind | No |
| Upstream Valve Type Ind | Manual |
| Downstream Valve Type Ind | Manual |
| Length Segment Isolated | 26 |
| Internal Inspection Ind | No |
| Unsuitable Mainline Ind | Yes |
| Other Inspection Ind | Yes |
| Internal Inspection Details | A Pig Launcher Is Installed At Pls-4, Which Allows Inspection On L-300b Between Mp 256.65-298.96 (Pls-4 To Pls-5). However, The Section Of L-300b South Of Pls-4 Is Not Currently Piggable Due To Lack Of A Launcher/receiver And Plug Valves Requiring Replacement. |
| Operation Complications Ind | No |
| Pipeline Function | Transmission System |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | No |
| Scada Conf Ind | Yes |
| Accident Identifier | Notification From Emergency Responder |
| 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 | Release of gas was due to a malfunctioned pressure relief valve and not due to the controller or control room issues |
| 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 |
| Relief Valve Ind | Yes |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Still Under Investigation |
| Preparer Name | C***** D**** |
| Preparer Title | Compliance Engineer |
| Preparer Email | C***@p**.com |
| Preparer Telephone | 925-328-5721 |
| Authorizer Name | L**** D******* |
| Authorizer Title | Manager Of Gas Operations Regulatory Compliance |
| Authorizer Telephone | 925-328-5756 |
| Authorizer Email | L***@p**.com |
| Narrative | On november 22, 2014 at 1652 hours an 8-inch pressure relief valve on pg&e's 34-inch transmission line l-300b at pressure limiting station 4-pls malfunctioned resulting in an unintentional release of natural gas to the atmosphere. Pg&e personnel arrived on scene at 1741 hours and the release of gas was stopped at 1948 hours by closing two bridal valves, which isolated the relief valve, allowing gas to bypass the relief valve through a mainline valve on the transmission line. No customers experienced gas service interruption. There were no injuries, no fatalities and no ignition as a result of this incident. A local residential clubhouse was evacuated by the fire department out of an abundance of caution. Local media was on scene during the incident. The pressure relief valve (prv) instrumentation tubing was replaced, its set points were re-tested, and a functional check out was completed by december 10, 2014. Prior to repairing the malfunctioning prv, overpressure protection was provided by controlling and restricting the natural gas pressure through 3-pls (the pressure limiting station upstream of 4-pls.) following the incident, pg&e contracted a third party engineering firm to perform a root cause analysis and provide recommendations to the station. Pg&e implemented several modifications and is currently in the design phase to rebuild pls-4. Pg&e inspects and calibrates pressure relief valves (prv) as part of pg&e's routine maintenance program, which is designed to ensure the reliable operation of this equipment at pg&e's pressure limiting stations. The unintentional release of natural gas is estimated to be approximately 119 million cubic feet (mmcf), therefore the incident was reported to the DOT and cpuc. |
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