Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2011-09-28 — OK
Operator
Questar Pipeline Company
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$0
Incident datetime
2011-09-28 09:50
Report number
Location
OK
Narrative
Supplemental being filed to clarify the cause of the incident. Discharge pressures from thistle creek compressor station were operating near the pre-set relief point of the thermal relief valve off the discharge gas coolers. The relief valve began to relieve. The situation was identified by an operating employee the next morning. The relief valve was isolated, manually reseated, and tested to be within 5% of its intended set-point. It was reset a little higher, within DOT limits, and operating pressures have not been near the setpoint since the incident occured. Initially, the estimated gas release was 3.79 mmscf, but upon finalizing the vented gas calculation, it was determined that the total volume of released gas was 2.28 mmscf. Questar pipeline company is filing this report to follow-up with the report made to the nrc, though the final vented gas volume was determined to be below the reporting threshold for unintentional releases.
Detailed record list
Report Received Date
2011-10-27 00:00:00
Iyear
2011
Report Number
20110380
Supplemental Number
16070
Report Type
Supplemental Final
Operator Id
12874
Name
Questar Pipeline Company
Operator Street Address
One Williams Center
Operator City Name
Tulsa
Operator State Abbreviation
OK
Operator Postal Code
74172
Local Datetime
2011-09-28 09:50:00
Location Latitude
39.81927
Location Longitude
-111.46463
Nrc Rpt Num
991083
Nrc Rpt Datetime
2011-09-28 13:26:00
Commodity Released Type
Natural Gas
Unintentional Release
2280
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Shutdown Explain
Relief Valve Line Was Isolated And The Valve Was Reseated Manually.
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2011-09-28 09:50:00
On Site Datetime
2011-09-28 09:50:00
On Off Shore
Onshore
Onshore State Abbreviation
Ut
Onshore Postal Code
84269
Onshore City Name
Indianola
Onshore County Name
Utah
Pipe Fac Name
Thistle Creek Compressor Station
Segment Name
Discharge Gas Cooler Thermal Relief
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
Relief Valve
Installation Year
2005
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Relief Valve Relieved Near Set-Point, But Did Not Re-Seat After The Pressure Dropped
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
20
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
8600
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
300
Est Cost Other
0
Prpty
8900
Accident Psig
1330
Mop Psig
1436
Mop Cfr Section
Not On Omb-Approved Form When Submitted
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
No
Scada Conf Ind
No
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Operator Employee
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
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary because the piping segment was being operated below maop and the relief valve is not remotely controlled.
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
Relief Valve Opened And Vented Gas, But Did Not Reseat Itself.
Preparer Name
C*** W******
Preparer Title
Supervisor Of Pipeline Compliance
Preparer Email
C***********@q******.com
Preparer Telephone
801-324-3814
Authorizer Name
L**** C****
Authorizer Title
Vice President Of Engineering And Operations
Authorizer Telephone
801-324-5061
Authorizer Email
L**********@q******.com
Narrative
Supplemental being filed to clarify the cause of the incident. Discharge pressures from thistle creek compressor station were operating near the pre-set relief point of the thermal relief valve off the discharge gas coolers. The relief valve began to relieve. The situation was identified by an operating employee the next morning. The relief valve was isolated, manually reseated, and tested to be within 5% of its intended set-point. It was reset a little higher, within DOT limits, and operating pressures have not been near the setpoint since the incident occured. Initially, the estimated gas release was 3.79 mmscf, but upon finalizing the vented gas calculation, it was determined that the total volume of released gas was 2.28 mmscf. Questar pipeline company is filing this report to follow-up with the report made to the nrc, though the final vented gas volume was determined to be below the reporting threshold for unintentional releases.
| Report Received Date | 2011-10-27 00:00:00 |
|---|---|
| Iyear | 2011 |
| Report Number | 20110380 |
| Supplemental Number | 16070 |
| Report Type | Supplemental Final |
| Operator Id | 12874 PHMSA Enforcement |
| Name | Questar Pipeline Company |
| Operator Street Address | One Williams Center |
| Operator City Name | Tulsa |
| Operator State Abbreviation | OK |
| Operator Postal Code | 74172 |
| Local Datetime | 2011-09-28 09:50:00 |
| Location Latitude | 39.81927 Google Maps OpenStreetMap |
| Location Longitude | -111.46463 Google Maps OpenStreetMap |
| Nrc Rpt Num | 991083 NRC Report How to search |
| Nrc Rpt Datetime | 2011-09-28 13:26:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 2280 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | No |
| Shutdown Explain | Relief Valve Line Was Isolated And The Valve Was Reseated Manually. |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2011-09-28 09:50:00 |
| On Site Datetime | 2011-09-28 09:50:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ut |
| Onshore Postal Code | 84269 |
| Onshore City Name | Indianola |
| Onshore County Name | Utah |
| Pipe Fac Name | Thistle Creek Compressor Station |
| Segment Name | Discharge Gas Cooler Thermal Relief |
| 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 | Relief Valve |
| Installation Year | 2005 |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Relief Valve Relieved Near Set-Point, But Did Not Re-Seat After The Pressure Dropped |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 20 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 8600 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 0 |
| Est Cost Emergency | 300 |
| Est Cost Other | 0 |
| Prpty | 8900 |
| Accident Psig | 1330 |
| Mop Psig | 1436 |
| Mop Cfr Section | Not On Omb-Approved Form When Submitted 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 | No |
| Scada Conf Ind | No |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Operator Employee |
| 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 | No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary because the piping segment was being operated below maop and the relief valve is not remotely controlled. |
| 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 | Relief Valve Opened And Vented Gas, But Did Not Reseat Itself. |
| Preparer Name | C*** W****** |
| Preparer Title | Supervisor Of Pipeline Compliance |
| Preparer Email | C***********@q******.com |
| Preparer Telephone | 801-324-3814 |
| Authorizer Name | L**** C**** |
| Authorizer Title | Vice President Of Engineering And Operations |
| Authorizer Telephone | 801-324-5061 |
| Authorizer Email | L**********@q******.com |
| Narrative | Supplemental being filed to clarify the cause of the incident. Discharge pressures from thistle creek compressor station were operating near the pre-set relief point of the thermal relief valve off the discharge gas coolers. The relief valve began to relieve. The situation was identified by an operating employee the next morning. The relief valve was isolated, manually reseated, and tested to be within 5% of its intended set-point. It was reset a little higher, within DOT limits, and operating pressures have not been near the setpoint since the incident occured. Initially, the estimated gas release was 3.79 mmscf, but upon finalizing the vented gas calculation, it was determined that the total volume of released gas was 2.28 mmscf. Questar pipeline company is filing this report to follow-up with the report made to the nrc, though the final vented gas volume was determined to be below the reporting threshold for unintentional releases. |
External Resources
PHMSA pipeline safety insights.
Product
Features
Company
All rights reserved. Copyright © by ClearPHMSA