Incident details
Operator, cause, commodity and consequences with raw source fields.
HL incident on 2023-11-02 — TX
Operator
Scm Operations, Llc
Cause
Equipment Failure
Commodity
Hvl Or Other Flammable Or Toxic Fluid Which Is A Gas At Ambient Conditions
Program
HL
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$39,112
Incident datetime
2023-11-02 00:00 UTC
Report number
Location
TX
Narrative
The release of ngl vapors occurred on the morning of september 21, 2023, as a result of a packing failure on the valve stem of a 24" gate valve on scm operations, llc's (scm) ngl transmission system in reeves county, texas. The event occurred after scm's downstream customer (enterprise) experienced a lightning strike that caused their valve at the receipt site to fail closed, which caused scm's 24" delivery valve to close on high differential. Scm's line pressure reached 1,327 psig, which is below the maop of the system of 1,480 psig. When enterprise was able to reset their system, scm's delivery valve (mov 0312) was then opened by scm's control room. The valve opening required 4 iterations of the open/close action over the course of a 17-minute time period. While the valve was being opened, enterprise's on-site technician heard a loud pop, observed a leak, and contacted scm. Scm personnel mobilized to site and instructed the control room to isolate the line segment by closing an isolation valve at the upstream valve setting. Upon arrival on site scm personnel confirmed discovery of a leak on valve mov 0312, and determined a blowdown of the line was necessary to effectuate repairs. The blowdown was initiated, and the pressure was drawn down by the following morning. A valve repair team inspected the failed valve and determined a replacement was necessary. A replacement valve was installed, and the line segment was placed back into service on september 24, 2023. Following the removal and disassembly of the failed valve an inspection revealed the seal between the graphite packing and the valve stem was compromised due to wear on the packing and roughness of the valve stem. The leak occurred when the compromised seal was breached after the multiple cycling attempts to open the valve. During the cycle attempts the expanding ngl would have cooled an estimated 0.1 deg f with a differential pressure of 50 psid. Based on the roughness of the stem, the reduced friction between the stem and the packing, rapid pressurization of the body cavity, and insufficient time for temperature to equalize, ngl likely migrated into the packing gland until the pipeline pressure of approximately 1,327 psig overcame the ability of the packing to maintain a seal. Valve stem roughness may have been a contributing factor to the wear on the packing, so the valve stem material was evaluated. It was identified to be aisi 4140, which is a low alloy steel and often selected for its toughness and high fatigue strength, however, it has a higher carbon content than a182 f6a or 17-4. Although aisi 4140 is within industry standards, an upgrade on the valve stem material to aisi 4140 with 3 mils of electroless nickel plating (enp), a182 f6a, or 17-4 is a possible design improvement that could lower the risk of a similar failure. Plan to prevent recurrence review of the isolation valves on scm's system identified one other valve with a stem that was of similar material. The stem cannot be visually examined during normal valve maintenance and inspection, therefore, scm will replace that valve with one that has a stem with improved metallurgical properties.
Detailed record list
Report Received Date
2023-11-02 00:00:00
Iyear
2023
Report Number
20230260
Supplemental Number
39153
Report Type
Supplemental Final
Operator Id
40204
Name
Scm Operations, Llc
Operator Street Address
5775 N Sam Houston Pkwy W Suite 600
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77086
Time Zone
Central
Daylight Savings Ind
Yes
Location Latitude
31.302179
Location Longitude
-103.10596
Commodity Released Type
Hvl Or Other Flammable Or Toxic Fluid Which Is A Gas At Ambient Conditions
Commodity Subtype
Lpg (Liquefied Petroleum Gas) / Ngl (Natural Gas Liquid)
Unintentional Release Bbls
54
Intentional Release Bbls
3929
Recovered Bbls
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Accident Identifier
Other
Accident Details
Notification From Downstream Customer's On Site Operations Technician
System Part Involved
Onshore Pipeline, Including Valve Sites
On Off Shore
Onshore
Status When Identified
Routine Start-Up
Shutdown Due Accident Ind
Yes
Communication State Fed Ind
Yes
Party Initiated Communication
Local/state/federal Emergency Responder
Nrc Rpt Num
1383152
Ignite Ind
No
Upstream Action Taken
Valve Closure
Upstream Valve Type Ind
Remotely Controlled
Downstream Action Taken
Valve Closure
Downstream Valve Type Ind
Remotely Controlled
Num Pub Evacuated
0
Pipe Fac Name
Waha Ii/enterprise Delivery
Segment Name
Waha Ii
Onshore State Abbreviation
Tx
Onshore Postal Code
79772
Onshore City Name
Not Within A Municipality
Onshore County Name
Reeves
Designated Location
Milepost
Designated Name
27.3
Federal
No
Location Type
Originated On Operator-Controlled Property, But Then Flowed Or Migrated Off The Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Intrastate
Item Involved
Valve
Valve Type
Mainline
Valve Mainline Type
Gate
Valve Manufacturer
Walworth
Installation Year
2019
Manufactured Year
2012
Material Involved
Material Other Than Carbon Steel
Material Details
Graphite
Release Type
Leak
Leak Type
Seal Or Packing
Wildlife Impact Ind
No
Soil Contamination
No
Long Term Assessment
No
Remediation Ind
No
Water Contam Ind
No
Could Be Hca
No
Commodity Reached Hca
No
Est Cost Oper Paid
0
Est Cost Gas Released
1296
Est Cost Prop Damage
39112
Est Cost Emergency
0
Est Cost Environmental
0
Est Cost Other
0
Prpty
40408
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Accident Psig
1327
Mop Psig
1480
Mop Cfr Section
Internal Design Pressure �195.406(A)(1)
Maop Established Date
2019-03-08 00:00:00
Maop Reversal Flow Ind
No
Accident Pressure
Pressure Did Not Exceed Mop
Pressure Restriction Ind
No
Length Segment Isolated
7524
Internal Inspection Ind
Yes
Operation Complications Ind
No
Pipeline Function
> 20% Smys Regulated Transmission
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Cpm In Place Ind
Yes
Cpm Operating Ind
Yes
Cpm Functional Ind
Yes
Cpm Detection Ind
No
Cpm Conf Ind
No
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
Leak was due to equipment failure.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Non-Threaded Connection Failure
Eq Failure Type
Non-Threaded Connection Failure
Other Non Threaded Ind
Seal (Not Pump Seal) Or Packing
Additional Erosion Wear Ind
Yes
Preparer Name
J*** H*****
Preparer Title
Director Of Compliance
Preparer Email
J**********@s****.com
Preparer Telephone
7135156916
Prepared Date
2024-02-05 00:00:00
Local Contact Name
J*** H*****
Local Contact Email
J**********@s****.com
Local Contact Telephone
7135156916
Authorizer Name
J*** H*****
Authorizer Telephone
7135156916
Authorizer Title
Director Of Compliance
Authorizer Email
J**********@s****.com
Narrative
The release of ngl vapors occurred on the morning of september 21, 2023, as a result of a packing failure on the valve stem of a 24" gate valve on scm operations, llc's (scm) ngl transmission system in reeves county, texas. The event occurred after scm's downstream customer (enterprise) experienced a lightning strike that caused their valve at the receipt site to fail closed, which caused scm's 24" delivery valve to close on high differential. Scm's line pressure reached 1,327 psig, which is below the maop of the system of 1,480 psig. When enterprise was able to reset their system, scm's delivery valve (mov 0312) was then opened by scm's control room. The valve opening required 4 iterations of the open/close action over the course of a 17-minute time period. While the valve was being opened, enterprise's on-site technician heard a loud pop, observed a leak, and contacted scm. Scm personnel mobilized to site and instructed the control room to isolate the line segment by closing an isolation valve at the upstream valve setting. Upon arrival on site scm personnel confirmed discovery of a leak on valve mov 0312, and determined a blowdown of the line was necessary to effectuate repairs. The blowdown was initiated, and the pressure was drawn down by the following morning. A valve repair team inspected the failed valve and determined a replacement was necessary. A replacement valve was installed, and the line segment was placed back into service on september 24, 2023. Following the removal and disassembly of the failed valve an inspection revealed the seal between the graphite packing and the valve stem was compromised due to wear on the packing and roughness of the valve stem. The leak occurred when the compromised seal was breached after the multiple cycling attempts to open the valve. During the cycle attempts the expanding ngl would have cooled an estimated 0.1 deg f with a differential pressure of 50 psid. Based on the roughness of the stem, the reduced friction between the stem and the packing, rapid pressurization of the body cavity, and insufficient time for temperature to equalize, ngl likely migrated into the packing gland until the pipeline pressure of approximately 1,327 psig overcame the ability of the packing to maintain a seal. Valve stem roughness may have been a contributing factor to the wear on the packing, so the valve stem material was evaluated. It was identified to be aisi 4140, which is a low alloy steel and often selected for its toughness and high fatigue strength, however, it has a higher carbon content than a182 f6a or 17-4. Although aisi 4140 is within industry standards, an upgrade on the valve stem material to aisi 4140 with 3 mils of electroless nickel plating (enp), a182 f6a, or 17-4 is a possible design improvement that could lower the risk of a similar failure. Plan to prevent recurrence review of the isolation valves on scm's system identified one other valve with a stem that was of similar material. The stem cannot be visually examined during normal valve maintenance and inspection, therefore, scm will replace that valve with one that has a stem with improved metallurgical properties.
| Report Received Date | 2023-11-02 00:00:00 |
|---|---|
| Iyear | 2023 |
| Report Number | 20230260 |
| Supplemental Number | 39153 |
| Report Type | Supplemental Final |
| Operator Id | 40204 PHMSA Enforcement |
| Name | Scm Operations, Llc |
| Operator Street Address | 5775 N Sam Houston Pkwy W Suite 600 |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77086 |
| Time Zone | Central |
| Daylight Savings Ind | Yes |
| Location Latitude | 31.302179 Google Maps OpenStreetMap |
| Location Longitude | -103.10596 Google Maps OpenStreetMap |
| Commodity Released Type | Hvl Or Other Flammable Or Toxic Fluid Which Is A Gas At Ambient Conditions |
| Commodity Subtype | Lpg (Liquefied Petroleum Gas) / Ngl (Natural Gas Liquid) |
| Unintentional Release Bbls | 54 |
| Intentional Release Bbls | 3929 |
| Recovered Bbls | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Accident Identifier | Other |
| Accident Details | Notification From Downstream Customer's On Site Operations Technician |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| On Off Shore | Onshore |
| Status When Identified | Routine Start-Up |
| Shutdown Due Accident Ind | Yes |
| Communication State Fed Ind | Yes |
| Party Initiated Communication | Local/state/federal Emergency Responder |
| Nrc Rpt Num | 1383152 NRC Report How to search |
| Ignite Ind | No |
| Upstream Action Taken | Valve Closure |
| Upstream Valve Type Ind | Remotely Controlled |
| Downstream Action Taken | Valve Closure |
| Downstream Valve Type Ind | Remotely Controlled |
| Num Pub Evacuated | 0 |
| Pipe Fac Name | Waha Ii/enterprise Delivery |
| Segment Name | Waha Ii |
| Onshore State Abbreviation | Tx |
| Onshore Postal Code | 79772 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Reeves |
| Designated Location | Milepost |
| Designated Name | 27.3 |
| Federal | No |
| Location Type | Originated On Operator-Controlled Property, But Then Flowed Or Migrated Off The Property |
| Incident Area Type | Aboveground |
| Incident Area Subtype | Typical Aboveground Facility Piping Or Appurtenance |
| Crossing | No |
| Pipe Facility Type | Intrastate |
| Item Involved | Valve |
| Valve Type | Mainline |
| Valve Mainline Type | Gate |
| Valve Manufacturer | Walworth |
| Installation Year | 2019 |
| Manufactured Year | 2012 |
| Material Involved | Material Other Than Carbon Steel |
| Material Details | Graphite |
| Release Type | Leak |
| Leak Type | Seal Or Packing |
| Wildlife Impact Ind | No |
| Soil Contamination | No |
| Long Term Assessment | No |
| Remediation Ind | No |
| Water Contam Ind | No |
| Could Be Hca | No |
| Commodity Reached Hca | No |
| Est Cost Oper Paid | 0 |
| Est Cost Gas Released | 1296 |
| Est Cost Prop Damage | 39112 |
| Est Cost Emergency | 0 |
| Est Cost Environmental | 0 |
| Est Cost Other | 0 |
| Prpty | 40408 |
| Num Persons Hosp Not Ovnght | 0 |
| Num Injured Treated By Emt | 0 |
| Num Resident Building Affctd | 0 |
| Num Business Building Affctd | 0 |
| Accident Psig | 1327 |
| Mop Psig | 1480 |
| Mop Cfr Section | Internal Design Pressure �195.406(A)(1) View CFR 49 §192 |
| Maop Established Date | 2019-03-08 00:00:00 |
| Maop Reversal Flow Ind | No |
| Accident Pressure | Pressure Did Not Exceed Mop |
| Pressure Restriction Ind | No |
| Length Segment Isolated | 7524 |
| Internal Inspection Ind | Yes |
| Operation Complications Ind | No |
| Pipeline Function | > 20% Smys Regulated Transmission |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | Yes |
| Scada Conf Ind | Yes |
| Cpm In Place Ind | Yes |
| Cpm Operating Ind | Yes |
| Cpm Functional Ind | Yes |
| Cpm Detection Ind | No |
| Cpm Conf Ind | No |
| 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 | Leak was due to equipment failure. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Equipment Failure |
| Cause Details | Non-Threaded Connection Failure |
| Eq Failure Type | Non-Threaded Connection Failure |
| Other Non Threaded Ind | Seal (Not Pump Seal) Or Packing |
| Additional Erosion Wear Ind | Yes |
| Preparer Name | J*** H***** |
| Preparer Title | Director Of Compliance |
| Preparer Email | J**********@s****.com |
| Preparer Telephone | 7135156916 |
| Prepared Date | 2024-02-05 00:00:00 |
| Local Contact Name | J*** H***** |
| Local Contact Email | J**********@s****.com |
| Local Contact Telephone | 7135156916 |
| Authorizer Name | J*** H***** |
| Authorizer Telephone | 7135156916 |
| Authorizer Title | Director Of Compliance |
| Authorizer Email | J**********@s****.com |
| Narrative | The release of ngl vapors occurred on the morning of september 21, 2023, as a result of a packing failure on the valve stem of a 24" gate valve on scm operations, llc's (scm) ngl transmission system in reeves county, texas. The event occurred after scm's downstream customer (enterprise) experienced a lightning strike that caused their valve at the receipt site to fail closed, which caused scm's 24" delivery valve to close on high differential. Scm's line pressure reached 1,327 psig, which is below the maop of the system of 1,480 psig. When enterprise was able to reset their system, scm's delivery valve (mov 0312) was then opened by scm's control room. The valve opening required 4 iterations of the open/close action over the course of a 17-minute time period. While the valve was being opened, enterprise's on-site technician heard a loud pop, observed a leak, and contacted scm. Scm personnel mobilized to site and instructed the control room to isolate the line segment by closing an isolation valve at the upstream valve setting. Upon arrival on site scm personnel confirmed discovery of a leak on valve mov 0312, and determined a blowdown of the line was necessary to effectuate repairs. The blowdown was initiated, and the pressure was drawn down by the following morning. A valve repair team inspected the failed valve and determined a replacement was necessary. A replacement valve was installed, and the line segment was placed back into service on september 24, 2023. Following the removal and disassembly of the failed valve an inspection revealed the seal between the graphite packing and the valve stem was compromised due to wear on the packing and roughness of the valve stem. The leak occurred when the compromised seal was breached after the multiple cycling attempts to open the valve. During the cycle attempts the expanding ngl would have cooled an estimated 0.1 deg f with a differential pressure of 50 psid. Based on the roughness of the stem, the reduced friction between the stem and the packing, rapid pressurization of the body cavity, and insufficient time for temperature to equalize, ngl likely migrated into the packing gland until the pipeline pressure of approximately 1,327 psig overcame the ability of the packing to maintain a seal. Valve stem roughness may have been a contributing factor to the wear on the packing, so the valve stem material was evaluated. It was identified to be aisi 4140, which is a low alloy steel and often selected for its toughness and high fatigue strength, however, it has a higher carbon content than a182 f6a or 17-4. Although aisi 4140 is within industry standards, an upgrade on the valve stem material to aisi 4140 with 3 mils of electroless nickel plating (enp), a182 f6a, or 17-4 is a possible design improvement that could lower the risk of a similar failure. Plan to prevent recurrence review of the isolation valves on scm's system identified one other valve with a stem that was of similar material. The stem cannot be visually examined during normal valve maintenance and inspection, therefore, scm will replace that valve with one that has a stem with improved metallurgical properties. |
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