Blue Ocean Oil is the approved representative for Stealth-Lock in Africa.

DESCRIPTION

Stealth-Lock™ MIF (Mechanical Interference Fit) mechanical connections have been widely applied in service over three decades. AGODCO has developed the MIF connections to be confidently acceptable for application with CS (carbon steel), FBE (fusion bonded epoxy), 3LPP (3 layer polypropylene) and PE (polyethylene) Liner applications. Our MIF connection is cold-formed from standard API 5L line pipe, with proven integrity and, at a construction rate of up to 2km per day per crew, it is unique in commercial and productivity values.

MATERIAL & STRENGTH DATA

TYPICAL GENERIC API PIPE GRADES

Grade B to X70; SMLS or ERW

DIAMETER SIZE RANGE

NPS 2-inch to 16-inch

TYPICAL DIAMETERS for FLOW-LINES

NPS 2 to 8-inch

TYPICAL WTs for Stealth-Lock™

Sch. 40 to Sch. 80

TYPICAL APPROVED PRESSURE CLASS

900# 175 barg

VALIDATED UYS test to failure (ISO 21329)*

594 to 902 barg

PRODUCTIVITY & PERFORMANCE DATA

STEALTH-LOCK™ JOINTS INSTALLED WORLDWIDE

>1,262,000 (updated 02.24)

STEALTH-LOCK™ LEAKS IN SERVICE WORLDWIDE

0

LTI’s SINCE 2011 INTRODUCTION FROM AGODCO

0

TYPICAL CONSTRUCTION PER DAY PER CREW

1-2 km

RT JOINT INSPECTION REQUIREMENT 0

0

LIGHT SANDSTORM WORK STOPPAGES

0

MANHOURS PER KM COMPARED TO WELDING

17%

GHGs EMISSIONS PER KM COMPARED TO WELDING 1.5%

18%

* Independent validation tests performed at STRESS Engineering Laboratory, Houston, Texas, USA.

Client Value Gains

  • 82% reduction of GHG emissions per km
  •  91% risk reduction for Lost Time Incidents
  • 91% reduction in “hot-works”
  • Well Hook-ups at double the usual rate
  • Project completions at 50% timeline
  • Production in service accelerated
  • Cash Conversion Cycle greatly reduced
  • Lower project investment capital employed
  • Supply-chain management reduced
  • Inventory management & cost reduction
  • Vertically Integrated project management

Contractor Value Gains

  • Reduce welding assets up to 80%
  • Reduce welding manpower up to 80%
  • Reduce food & accommodation costs by 70%
  • Reduce transportation costs by 50%
  • Complete projects in 50% of timeline
  • Accelerate cashflow by 200%
  • Increase profit from marginal to circa 25%
  • 91% risk reduction for Lost Time Incidents
  • 83% risk reduction for Covid virus transmission

Click below for more technical details.

www.stealthlock.us

 

FAQs for Stealth-Lock™ 2025

What, Where & How

It is a fast Mechanical Interference Fit (MIF) connection that doesn’t require welding, increase his productivity, reduces hazard and risk and reduces project costs for carbon steel pipeline construction.

A Mechanical Interference Fitting connection is a strong and reliable system that derives from relying on radial compressive elastic and plastic residual stresses and surface friction properties of steel. This is caused by inserting an oversized male carbon steel tube (the “Pin”) into an undersized female carbon steel tube (the “Bell”).

For carbon steel pipeline projects typically associated with hydrocarbon field development, gathering systems and transport pipelines. Put simply it’s good for Oil, Gas and Water high pressure production and water injection pipelines

The Stealth-Lock™ MIF system is applied on API 5L Carbon Steel Line Pipe (or international equivalent specifications). It is compliant to ISO 21329 (International standard governing mechanical connectors).

Sizes, Materials, Machinery

Our Stealth-Lock™ Hydraulic equipment is designed and manufactured in four different size ranges that cover diameters as low as Nominal Pipe Size (NPS) 2-inches all the way up to NPS 16-inches. The equipment spread models are:
• SL26 (2 to 6-inches diameter)
• SL28 (2 to 8-inches diameter)
• SL410 SL26 (4 to 10-inches diameter)
• SL SL1016 (10 to 16-inches diameter)

Typical applications range from API 5L Grade B through X42, X52, X65 but depending on diameter and wall thicknesses (WT), higher grades of carbon steel pipes can be applied with Stealth-Lock™. The pipe wall thickness we typically quote “from schedule 40 to schedule 80” but again, depending on diameters and pipe grades these parameters can be less than schedule 40 and greater than schedule 80.

Process & Productivity

Typically, we will be supplied with “free issue” pipes from the client. We refer to the first process as “prepping”. This is where we will clamp one end of each pipe and insert a mandrel to expand that pipe and create “the Bell”. At the other end of the pipe we will either trim a taper or mechanically swage the pipe to form what we call. “the Pin”.

After prepping, the pipes will either be sent for coating applications or as bare pipes directly to the project location. At site, we will utilize our SL Assembly machine and hydraulic power unit to mechanically grip the mating pipes and force fit them together.

Typically, Stealth-Lock™ installation crews can achieve up to 2 km per day onshore. Faster/slower productivity also depends on usual site conditions such as; congestion, topography, and terrain. If you take a typical 6 inch flowline project, in open virgin territory with few obstacles, we would expect to be above 2 km in one 10 hours dayshift. Depending on individual pipe length, we would expect a typical Welding crew to deliver 180 m to 200 m of connected pipeline in the same dayshift.

Corrosion & Coatings

Stealth-Lock™ performs very well in sour service conditions when applied with internal (ID) coatings such as Fusion Bonded Epoxy (FBE). The technology is also approved for application together with polyethylene (PE) liners, in both tight and loose liner categories. Because FBE is applied after prepping the pipes, Stealth-Lock™ has engineered a special application process for the coating applicator and this results in a holiday free interlocking connection without the need for expensive circumferential Welding sleeves.

Again, as with the ID, the system performs very well with external (OD) coatings such as FBE. Where thicker corrosion or sacrificial barriers are required, the system works very well with, 3-layer polypropylene (3LPP) coated pipes. 3LPP is usually applied in oil fields where the resources are drawn from deep reservoirs and at high temperatures (100°C to 140°C). It is highly abrasion resistant and is generally used where the chances of damage are high such as rocky terrain.

No. For engineering design with corrosion barriers Stealth-Lock™ can be considered as the same or better performance as a welded connection.

Independent Testing & Validation

Yes. High confidence and pipeline integrity is at the vanguard of our Stealth-Lock™ MIF system. Since 2010, we have worked with independent research and testing laboratories such as Stress Engineering Services based in Houston, Texas. A well renowned leader in mechanical testing of force, load, tension, pressure, fatigue and temperature. Our R&D engineers have worked alongside Stress Engineering in a combined effort to maximise and validate the performance envelopes of the Stealth-Lock™ technology. Stress Engineering test results are completely independent, objective, and trusted by all major oil and gas client operators, worldwide.

In addition to Stress Engineering, we also rely upon specialist expertise that sits with Southwest Research Institute (SwRI), headquartered in San Antonio, Texas. We also credit our Global Value Chain partner; Tenaris (the world’s largest tubular goods manufacturer) who has independently verified Stealth-Lock™ for its application with Tenaris pipes across Latin America to hydrocarbon operators from Argentina to Mexico.

Since 2010, and navigating through many validation and qualification projects for different client operators, the system has been repeatedly independently validated based on the following typical standards and specifications:

• Installation Tests ISO 21329
• Operational Restrained & Unrestrained Tests ISO 21329
• Hydrostatic Pressure Tests ISO 21329
• Limit Load Tests ISO 21329
• Fatigue Tests. BS7608 and DNV C203
• Pressure, Axial Load, Bending ISO 13679:2002(E)
• Electrochemical Impedance Spectroscopy Test (EIS)
• Tensile, Charpy & Hardness Tests API 5L and ISO 3183
• Sulphide Stress Cracking (SSC) NACE TM0177

On occasions since 2010, third-party evaluation validation and reporting has resulted in a high level of confidence for Stealth-Lock™ MIF as being a reliable alternative to standard welded connections across the diameter ranges. Furthermore, Integrity performance as often outperformed welded connections and the generic conclusions of all third-party testing are as follows:

From the testing performed, we can conclude:
• No permanent plastic deformations are done during joining. Once the ends are conformed in the mill, the connection works always in the elastic range.
• The Stealth Lock connection passed satisfactory all the testing done under ISO 21329, that represent conditions that are more severe than the ones found on the field.
• It was proved that structural and seal ability resistance is maintained even under extreme doglegs (up to 79°/100ft).
• In the operational loads, the connection proved its gas seal ability (N2) both on restrained and unrestrained tests.
• In the limit load tests, the connection always failed at values beyond the pipe’s yielding point, withstanding loads that by design the pipe should never be exposed to.
• Tests performed at low temperatures were useful to guarantee

From the analysis performed, we can conclude:
• During assembly, no permanent plastic deformations are generated. Once the ends have been shaped in the mill, the joint will always behave in the elastic range.
• The Stealth Lock connection successfully passed all tests carried out under the guidelines of ISO 21329, which represent more severe loading conditions than those found in the field.
• It was shown that under extreme bending conditions (up to 79 ° / 30m) the joint maintained its structural strength and seal ability.
• In operating load tests, the joint demonstrated gas seal ability (N2) for both, restricted and unrestricted operations.
• In the limit load tests, the connection always failed at values higher than the yield strength of the pipe body, withstanding loads to which the pipeline should never be exposed by design.
• Low temperature tests were useful to ensure that the technology maintains its robustness and is perfectly applicable in environments that reach temperatures down to -20 °C. This is concluded since:
• In impact tests, the joint behaved in a ductile way.
• In the internal pressure tests, the joint always failed having plasticized the pipe body first.

Design, Performance & Integrity

The abundance of validation data generated from years of continual testing, both third-party and field hydrotesting evidence that the performance of the Stealth-Lock™ connection is at least equal to, if not better than a C2 welded connection. To support this assertion, the performance data across testing and in-service conditions, continues to evidence that Stealth-Lock™ MIF, most often performs better than welded connections. From time to time, stress analysis has been requested from clients wishing to validate the technology. On each occasion this evidences the fact that Stealth Lock MIF should be considered as comparable if not better than C2 welded connections.

Axial Tension Capacity: The axial tension capacity of the Stealth-Lock™ MIF connection increases with pressure and the insertion depth. The axial tension capacity is above 90% of the ultimate tensile strength of the parent pipe. However, this metric can be improved by increasing the specific insertion depth and by being in service at high pressure as this assists the axial tension that is the friction between Bell and Pin (to a certain point).

Pressure Rating: The pressure capacity of the Stealth-Lock™ connection is the same as the parent pipe since it has been proven to be an effective “positive seal.”

Bending Capacity: Depending on the pipe diameter and the wall thickness, bending of the Stealth-Lock™ connection performs well under the conditions imposed on mechanical installation tests (ISO 21329). Bending induced stresses will differ greatly depending on diameter, grade and wall thickness but Stealth-Lock™ performs well across all categories.

Compression Capacity: The compressive capacity of the Stealth-Lock™ connection is the same as the parent pipe since it is effectively a positive seal.

Fatigue Capacity: The connection can confidently be considered as a C2 class weld.

Over the years there have been many destructive tests performed on Stealth-Lock™ connections. Ultimate performance will always be variable depending on diameter, wall thickness, and pipe grades. There are too many tests to list so what we can state is that the minimum pressure where the connection yielded on a destructive pressure to failure test was 594 bar. That test was performed at stress engineering in Houston, Texas and the sample coupon was NPS 6-inch X52 WT 6.1mm.

It is a fast Mechanical Interference Fit (MIF) connection that doesn’t require welding, increase his productivity, reduces hazard and risk and reduces project costs for carbon steel pipeline construction.

A Mechanical Interference Fitting connection is a strong and reliable system that derives from relying on radial compressive elastic and plastic residual stresses and surface friction properties of steel. This is caused by inserting an oversized male carbon steel tube (the “Pin”) into an undersized female carbon steel tube (the “Bell”).

For carbon steel pipeline projects typically associated with hydrocarbon field development, gathering systems and transport pipelines. Put simply it’s good for Oil, Gas and Water high pressure production and water injection pipelines.

The Stealth-Lock™ MIF system is applied on API 5L Carbon Steel Line Pipe (or international equivalent specifications). It is compliant to ISO 21329 (International standard governing mechanical connectors).

References & Qualifications

Our Stealth-Lock™ System has been in wide use, across the Middle East and Latin America for the last 14 years. With operator majors such as ADNOC, Petroleum Development Oman (PDO), Occidental and Tatweer Petroleum, having zero failures in service and full trust and confidence in the technology.

For Latin America, the technology is licensed to the world’s largest tubular goods manufacturer, Tenaris. Before accepting the license agreement, Tenaris having conducted several years of in-house testing and validation to prove the integrity of the connection system itself.

For historical references before AGODCO aquired the technology in 2010 there are many worldwide operators utilising the technology since 1970s.

• Amoco Production Company & Panhandle Eastern
• Amereda Hess
• PennWest Energy
• JSC Bashneft
• Lukoil
• Vecto Services Company

• Joint Stock Oil Company BASHNEFT
– BASHNEFT Yanual
– BASHNEFT Ufa
– BASHNEFT Ishimbay
– BASHNEFT Belkamneft

• Open Joint Stock Company Lukoil
– Lukoil West Siberia
– Lukoil Langepasneftegas
– Lukoil Kogalymneftegas
– Uraineftegas
– Komi
– Perm

• Open Joint Stock Company Tatneft
– Tatneft Almetyevneft
– Tatneft Aznakaevneft
– Tatneft Bavlyneft
– Tatneft Djalineft
– Tatneft Elhovneft
– Tatneft Leninogorskneft
– Tatneft Nurlatneft
– Tatneft Prikamneft
– Tatneft Yamashneft

• Pemex (PEP)
• Perenco Colombia
• Emerald Energy
• Pacific Rubiales Energy Colombia
• Tatweer Petroleum (OXY, Mubadala, NOGA Holdings)
• CC Energy Development
• Petroleum Development Oman (PDO Shell)
• Occidental Oman (OXY)
• Promegas (Sure-Lock Brand)
• Abu Dhabi National Oil Company (ADNOC)
• Stealth-Lock™ via TENARIS: Yacimientos Petrolíferos Fiscales (YPF)
• Stealth-Lock™ via TENARIS: Tecpetrol
• Stealth-Lock™ via TENARIS: Pan American Energy (BP)
• Stealth-Lock™ via TENARIS: Compañía General de Combustibles (GGC)