Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2016-02-10 — MI
Operator
Consumers Energy Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$4,563
Incident datetime
2016-02-10 04:49
Report number
Location
MI
Narrative
On february 10, 2016 at approximately 04:49 consumers energy gas control received a scada alarm identifying a possible over pressure event on the adams rd. Outlet at the coolidge city gate. The coolidge city gate is located at 4600 coolidge hwy., (oakland county) royal oak, michigan. An instrument mechanic (im) was dispatched at approximately 04:52 and arrived on location at approximately 05:53 to discover a failure of the primary regulator (p2). The regulator failure caused the relief valve (rv- 6) serving the adams rd., outlet to activate and remain open until approximately 06:18. The responding im performed a valving operation to isolate the failed regulator allowing the standby regulator (s2) to feed. The pressure on the adams rd. Outlet increased to a maximum of 318.37 psig and approximately 4.2 mmcf of natural gas was vented to the atmosphere as a result of the incident. The initial investigation of the failure suggested the inlet screen on the adams rd. Outlet main run regulator (p2) was partially disintegrated causing metal debris to contaminate the regulators internal components causing it to fail open. The p2 regulator was cleaned of debris and the inlet screen and regulator diaphragm were replaced. The equipment was tested and return to service. The impacted relief valve was also disassemble and checked for damage and debris with negative results. At approximately 04:42 the following day the p2 regulator experienced another failure. The relief valve operated as a result of the exceedance. However, hydrates entrained in the gas stream were found to have precipitated out and froze in the relief valve's pilot resulting in delayed activation. The pressure on the adams rd. Outlet increased to a maximum of 338 psig for approximately two minutes before returning to a steady relief pressure below 110% of maop. The relief valve was cleaned, rebuilt, inspected and return to service. Regulator p2 has been removed from service until further investigation and lab analysis is complete and appropriate remediation actions identified. A safety related condition report detailing the failure that occurred on february 11th was reported to PHMSA on february 18, 2016 (scrc 20160022). A mobile and walking survey was performed on approximately 1.5 miles of 12" steel high pressure distribution piping (300 psig maop) operating at > 20% smys and associated service lines between the coolidge city gate and maple rd., troy, michigan and no leaks were detected. The regulation equipment (regulator p2) removed from service on february 11, 2016 was replaced with a mooney flowgrid regulator on august 8, 2016 and returned to normal operations. The regulator, diaphragm and cage were examined by consumers energy laboratory services, in september 2016. The investigation found the diaphragm dimensions were inconsistent with the dimensions of the cage, preventing a secure fit during assembly. In addition, measurement data indicated the o-ring assembled on the bonnet was not subject to compression during assembly. The investigation was inconclusive as to why the diaphragm was out of position, and no failure cause was identified. A safety-related condition report "return to service" notice detailing remediation activities was submitted on february 28, 2017.
Detailed record list
Report Received Date
2016-03-11 00:00:00
Iyear
2016
Report Number
20160019
Supplemental Number
17315
Report Type
Supplemental Final
Operator Id
2748
Name
Consumers Energy Co
Operator Street Address
One Energy Plaza
Operator City Name
Jackson
Operator State Abbreviation
MI
Operator Postal Code
49201
Local Datetime
2016-02-10 04:49:00
Location Latitude
42.531189
Location Longitude
-83.183859
Nrc Rpt Num
1140177
Nrc Rpt Datetime
2016-02-10 09:43:00
Commodity Released Type
Natural Gas
Unintentional Release
4200
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
No
Shutdown Explain
Relief Valve Activated - Shut-Down Not Required
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2016-02-10 04:49:00
On Site Datetime
2016-02-10 05:53:00
On Off Shore
Onshore
Onshore State Abbreviation
Mi
Onshore Postal Code
48073
Onshore City Name
Royal Oak
Onshore County Name
Oakland
Designated Location
Milepost
Designated Name
Coolidge Cg
Pipe Fac Name
Coolidge City Gate
Segment Name
Line 1017
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Inside A Building
Crossing
No
Pipe Facility Type
Intrastate
System Part Involved
Onshore Regulator/metering Station Equipment And Piping
Item Involved
Regulator/control Valve
Installation Year
1985
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Regulation Equipment Failure - 6" Fisher Ezr Regulator
Class Location Type
Class 3 Location
Could Be Hca
Yes
Determination Method
Method2
Pir Radius
143
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
31332
Est Cost Intentional Release
0
Est Cost Prop Damage
4563
Est Cost Emergency
200
Est Cost Other
7976
Est Cost Other Details
Laboratory Analysis
Prpty
44071
Accident Psig
318
Mop Psig
300
Mop Cfr Section
192.619(A)(2)
Accident Pressure
Pressure Exceeded Maop, But Did Not Exceed The Applicable Allowance In 192.201
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 control room operator identified the pressure increase and notified the appropriate personnel
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
Pressure Regulator Ind
Yes
Eq Additional Other Ind
Yes
Eq Additional Other Details
Dimensional Anomaly With The Regulator Diaphragm And The Regulator Body
Preparer Name
C******* K***
Preparer Title
Senior Engineering Technical Analyst I
Preparer Email
C************@c********.com
Preparer Telephone
517-788-0509
Authorizer Name
A***** L* W***
Authorizer Title
Gas Regulatory Services Lead
Authorizer Telephone
517-545-8746
Authorizer Email
A**********@c********
Narrative
On february 10, 2016 at approximately 04:49 consumers energy gas control received a scada alarm identifying a possible over pressure event on the adams rd. Outlet at the coolidge city gate. The coolidge city gate is located at 4600 coolidge hwy., (oakland county) royal oak, michigan. An instrument mechanic (im) was dispatched at approximately 04:52 and arrived on location at approximately 05:53 to discover a failure of the primary regulator (p2). The regulator failure caused the relief valve (rv- 6) serving the adams rd., outlet to activate and remain open until approximately 06:18. The responding im performed a valving operation to isolate the failed regulator allowing the standby regulator (s2) to feed. The pressure on the adams rd. Outlet increased to a maximum of 318.37 psig and approximately 4.2 mmcf of natural gas was vented to the atmosphere as a result of the incident. The initial investigation of the failure suggested the inlet screen on the adams rd. Outlet main run regulator (p2) was partially disintegrated causing metal debris to contaminate the regulators internal components causing it to fail open. The p2 regulator was cleaned of debris and the inlet screen and regulator diaphragm were replaced. The equipment was tested and return to service. The impacted relief valve was also disassemble and checked for damage and debris with negative results. At approximately 04:42 the following day the p2 regulator experienced another failure. The relief valve operated as a result of the exceedance. However, hydrates entrained in the gas stream were found to have precipitated out and froze in the relief valve's pilot resulting in delayed activation. The pressure on the adams rd. Outlet increased to a maximum of 338 psig for approximately two minutes before returning to a steady relief pressure below 110% of maop. The relief valve was cleaned, rebuilt, inspected and return to service. Regulator p2 has been removed from service until further investigation and lab analysis is complete and appropriate remediation actions identified. A safety related condition report detailing the failure that occurred on february 11th was reported to PHMSA on february 18, 2016 (scrc 20160022). A mobile and walking survey was performed on approximately 1.5 miles of 12" steel high pressure distribution piping (300 psig maop) operating at > 20% smys and associated service lines between the coolidge city gate and maple rd., troy, michigan and no leaks were detected. The regulation equipment (regulator p2) removed from service on february 11, 2016 was replaced with a mooney flowgrid regulator on august 8, 2016 and returned to normal operations. The regulator, diaphragm and cage were examined by consumers energy laboratory services, in september 2016. The investigation found the diaphragm dimensions were inconsistent with the dimensions of the cage, preventing a secure fit during assembly. In addition, measurement data indicated the o-ring assembled on the bonnet was not subject to compression during assembly. The investigation was inconclusive as to why the diaphragm was out of position, and no failure cause was identified. A safety-related condition report "return to service" notice detailing remediation activities was submitted on february 28, 2017.
| Report Received Date | 2016-03-11 00:00:00 |
|---|---|
| Iyear | 2016 |
| Report Number | 20160019 |
| Supplemental Number | 17315 |
| Report Type | Supplemental Final |
| Operator Id | 2748 PHMSA Enforcement |
| Name | Consumers Energy Co |
| Operator Street Address | One Energy Plaza |
| Operator City Name | Jackson |
| Operator State Abbreviation | MI |
| Operator Postal Code | 49201 |
| Local Datetime | 2016-02-10 04:49:00 |
| Location Latitude | 42.531189 Google Maps OpenStreetMap |
| Location Longitude | -83.183859 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1140177 NRC Report How to search |
| Nrc Rpt Datetime | 2016-02-10 09:43:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 4200 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | No |
| Shutdown Explain | Relief Valve Activated - Shut-Down Not Required |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2016-02-10 04:49:00 |
| On Site Datetime | 2016-02-10 05:53:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Mi |
| Onshore Postal Code | 48073 |
| Onshore City Name | Royal Oak |
| Onshore County Name | Oakland |
| Designated Location | Milepost |
| Designated Name | Coolidge Cg |
| Pipe Fac Name | Coolidge City Gate |
| Segment Name | Line 1017 |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Aboveground |
| Incident Area Subtype | Inside A Building |
| Crossing | No |
| Pipe Facility Type | Intrastate |
| System Part Involved | Onshore Regulator/metering Station Equipment And Piping |
| Item Involved | Regulator/control Valve |
| Installation Year | 1985 |
| Material Involved | Carbon Steel |
| Release Type | Other |
| Release Type Details | Regulation Equipment Failure - 6" Fisher Ezr Regulator |
| Class Location Type | Class 3 Location |
| Could Be Hca | Yes |
| Determination Method | Method2 |
| Pir Radius | 143 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 31332 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 4563 |
| Est Cost Emergency | 200 |
| Est Cost Other | 7976 |
| Est Cost Other Details | Laboratory Analysis |
| Prpty | 44071 |
| Accident Psig | 318 |
| Mop Psig | 300 |
| Mop Cfr Section | 192.619(A)(2) View CFR 49 §192 |
| Accident Pressure | Pressure Exceeded Maop, But Did Not Exceed The Applicable Allowance In 192.201 |
| 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 control room operator identified the pressure increase and notified the appropriate personnel |
| 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 |
| Pressure Regulator Ind | Yes |
| Eq Additional Other Ind | Yes |
| Eq Additional Other Details | Dimensional Anomaly With The Regulator Diaphragm And The Regulator Body |
| Preparer Name | C******* K*** |
| Preparer Title | Senior Engineering Technical Analyst I |
| Preparer Email | C************@c********.com |
| Preparer Telephone | 517-788-0509 |
| Authorizer Name | A***** L* W*** |
| Authorizer Title | Gas Regulatory Services Lead |
| Authorizer Telephone | 517-545-8746 |
| Authorizer Email | A**********@c******** |
| Narrative | On february 10, 2016 at approximately 04:49 consumers energy gas control received a scada alarm identifying a possible over pressure event on the adams rd. Outlet at the coolidge city gate. The coolidge city gate is located at 4600 coolidge hwy., (oakland county) royal oak, michigan. An instrument mechanic (im) was dispatched at approximately 04:52 and arrived on location at approximately 05:53 to discover a failure of the primary regulator (p2). The regulator failure caused the relief valve (rv- 6) serving the adams rd., outlet to activate and remain open until approximately 06:18. The responding im performed a valving operation to isolate the failed regulator allowing the standby regulator (s2) to feed. The pressure on the adams rd. Outlet increased to a maximum of 318.37 psig and approximately 4.2 mmcf of natural gas was vented to the atmosphere as a result of the incident. The initial investigation of the failure suggested the inlet screen on the adams rd. Outlet main run regulator (p2) was partially disintegrated causing metal debris to contaminate the regulators internal components causing it to fail open. The p2 regulator was cleaned of debris and the inlet screen and regulator diaphragm were replaced. The equipment was tested and return to service. The impacted relief valve was also disassemble and checked for damage and debris with negative results. At approximately 04:42 the following day the p2 regulator experienced another failure. The relief valve operated as a result of the exceedance. However, hydrates entrained in the gas stream were found to have precipitated out and froze in the relief valve's pilot resulting in delayed activation. The pressure on the adams rd. Outlet increased to a maximum of 338 psig for approximately two minutes before returning to a steady relief pressure below 110% of maop. The relief valve was cleaned, rebuilt, inspected and return to service. Regulator p2 has been removed from service until further investigation and lab analysis is complete and appropriate remediation actions identified. A safety related condition report detailing the failure that occurred on february 11th was reported to PHMSA on february 18, 2016 (scrc 20160022). A mobile and walking survey was performed on approximately 1.5 miles of 12" steel high pressure distribution piping (300 psig maop) operating at > 20% smys and associated service lines between the coolidge city gate and maple rd., troy, michigan and no leaks were detected. The regulation equipment (regulator p2) removed from service on february 11, 2016 was replaced with a mooney flowgrid regulator on august 8, 2016 and returned to normal operations. The regulator, diaphragm and cage were examined by consumers energy laboratory services, in september 2016. The investigation found the diaphragm dimensions were inconsistent with the dimensions of the cage, preventing a secure fit during assembly. In addition, measurement data indicated the o-ring assembled on the bonnet was not subject to compression during assembly. The investigation was inconclusive as to why the diaphragm was out of position, and no failure cause was identified. A safety-related condition report "return to service" notice detailing remediation activities was submitted on february 28, 2017. |
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