Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2011-07-21 — 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
2011-07-21 02:45
Report number
Location
OK
Narrative
Using scada information, control room personnel found a drop in pressure. They dispatched operational personnel to investigate the issue. The operational personnel found a relief valve releasing gas even though the pressure was below the relief set point. Operational personnel found an obstruction in the relief valve 3/8" tube sensing line causing the relief valve to open prematurely. Operational personnel repaired the issue and returned the relief valve to proper operations.
Detailed record list
Report Received Date
2011-08-19 00:00:00
Iyear
2011
Report Number
20110297
Supplemental Number
16071
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
2011-07-21 02:45:00
Location Latitude
41.52412
Location Longitude
-109.319577
Nrc Rpt Num
983448
Nrc Rpt Datetime
2011-07-21 17:25:00
Commodity Released Type
Natural Gas
Unintentional Release
22000
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2011-07-21 02:45:00
On Site Datetime
2011-07-21 03:15:00
On Off Shore
Onshore
Onshore State Abbreviation
Wy
Onshore Postal Code
82901
Onshore City Name
Rock Springs
Onshore County Name
Sweetwater
Pipe Fac Name
Kanda Compressor Station
Segment Name
Unit 4 Discharge Piping
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
Esd System, But Excluding Product Drain Lines And Tubing
Installation Year
1981
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
There Was An Obstruction In The 3/8" Tube Sensing Line Of The Relief Valve, Causing The Relief Valve To Open.
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
146
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
91350
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
100
Est Cost Other
0
Prpty
91450
Accident Psig
930
Mop Psig
1025
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
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
The controller's actions did not contribute but rather assisted in determining the cause of the incident. The incident was caused by an obstruction in the 3/8" tube sensing line of the relief valve, causing the relief valve to open.
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
Obstruction In The 3/8" Tube Sensing Line Of The Relief Valve
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 - Engineering And Operations
Authorizer Telephone
801-324-5061
Authorizer Email
L**********@q******.com
Narrative
Using scada information, control room personnel found a drop in pressure. They dispatched operational personnel to investigate the issue. The operational personnel found a relief valve releasing gas even though the pressure was below the relief set point. Operational personnel found an obstruction in the relief valve 3/8" tube sensing line causing the relief valve to open prematurely. Operational personnel repaired the issue and returned the relief valve to proper operations.
| Report Received Date | 2011-08-19 00:00:00 |
|---|---|
| Iyear | 2011 |
| Report Number | 20110297 |
| Supplemental Number | 16071 |
| 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 | 2011-07-21 02:45:00 |
| Location Latitude | 41.52412 Google Maps OpenStreetMap |
| Location Longitude | -109.319577 Google Maps OpenStreetMap |
| Nrc Rpt Num | 983448 NRC Report How to search |
| Nrc Rpt Datetime | 2011-07-21 17:25:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 22000 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | No |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2011-07-21 02:45:00 |
| On Site Datetime | 2011-07-21 03:15:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Wy |
| Onshore Postal Code | 82901 |
| Onshore City Name | Rock Springs |
| Onshore County Name | Sweetwater |
| Pipe Fac Name | Kanda Compressor Station |
| Segment Name | Unit 4 Discharge Piping |
| 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 | Esd System, But Excluding Product Drain Lines And Tubing |
| Installation Year | 1981 |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | There Was An Obstruction In The 3/8" Tube Sensing Line Of The Relief Valve, Causing The Relief Valve To Open. |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 146 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 91350 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 0 |
| Est Cost Emergency | 100 |
| Est Cost Other | 0 |
| Prpty | 91450 |
| Accident Psig | 930 |
| Mop Psig | 1025 |
| 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 | 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 | The controller's actions did not contribute but rather assisted in determining the cause of the incident. The incident was caused by an obstruction in the 3/8" tube sensing line of the relief valve, causing the relief valve to open. |
| 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 | Obstruction In The 3/8" Tube Sensing Line Of The Relief Valve |
| 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 - Engineering And Operations |
| Authorizer Telephone | 801-324-5061 |
| Authorizer Email | L**********@q******.com |
| Narrative | Using scada information, control room personnel found a drop in pressure. They dispatched operational personnel to investigate the issue. The operational personnel found a relief valve releasing gas even though the pressure was below the relief set point. Operational personnel found an obstruction in the relief valve 3/8" tube sensing line causing the relief valve to open prematurely. Operational personnel repaired the issue and returned the relief valve to proper operations. |
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