Applications

Lokring-Coldweld™ fittings are engineered to perform where the stakes are highest — in critical piping systems across oil and gas, marine, healthcare, defense, and industrial applications. That performance is independently verified.

We partner with the world’s foremost approval and certification bodies to ensure our products meet, and often exceed, the rigorous standards that govern your industry. From ISO 9001:2015 quality management to NAVSEA, ABS, Lloyd’s Register, DNV, ASME B31, NSF, and beyond, Lokring holds a comprehensive portfolio of approvals earned through decades of qualification testing and real-world field performance.

At the core of every Lokring fitting is proprietary Elastic Strain Preload (ESP®) technology — the engineering principle that creates a permanent, helium leak-tight, metal-to-metal seal without heat, flames, or fire permits. It’s the same weld-equivalent connection trusted by the U.S. Navy, major oil and gas operators, and healthcare facilities worldwide.

Applications of Lokring Pipe & Tube Fittings

Lokring fittings, engineered with proprietary Elastic Strain Preload (ESP®) technology, deliver weld-equivalent performance without heat, enabling durable, metal-to-metal seals across piping systems without the need for welding or flanges. Explore the approvals and qualification testing details below by product group, or contact us with specific questions.

Industrial Utility & Process Piping

Lokring connectors are trusted across a variety of major piping systems, including:

  • Chemical processing, hydrocarbons, steam, gas, cryogenics, and utilities
  • Applications in chemical plants, loading terminals, bulk storage, pulp & paper, food processing, refineries, and petrochemical facilities
  • Compatibility with ASME B31 Codes: B31.1 (Power), B31.3 (Process), B31.4 (Liquid Hydrocarbons), B31.8 (Gas Transmission), and B31.9 (Building Services)

Installation & Repairs

Our products are ideal for MRO applications where rapid deployment and retrofitting are needed.  In these situations, Lokring:

  • Eliminates hot work, fire watches, and nitrogen purging—delivering up to 40% labor savings compared to traditional welding methods
  • Requires only cutting, sanding, and hydraulic tooling—enabling quick, field-friendly installations using a five-step process
  • Features “thru-bore” couplings (≥ ¼ ”) that slide over pipe/tube ends effortlessly—especially beneficial for repair work

Sealing Integrity & Environmental Safety

Lokring’s metal-to-metal seal ensures:

  • Exceptional reliability in both gas and liquid services
  • No O-rings, gaskets, or elastomeric materials—eliminating degradation from heat, vibration, or chemical exposure
  • Superior leak prevention: meets or exceeds helium leak test standards and is CARB pre-certified as weld-equivalent

 

Heavy-Duty Industry Credentials & Approvals

Lokring product approvals and certifications extend into rigorous sectors:

  • Railroad: AAR-approved for freight car interchange use since 1997, surviving burst, vibration, thermal, torsion, fire, and corrosive tests
  • Marine/Refrigeration: U.S. Coast Guard–approved for onboard HVAC systems; meets MIL‑STD‑777
  • Global Industries: Proven use in shipbuilding, oil & gas (upstream/downstream), nuclear, pharmaceuticals, steel, medical gas systems, and beyond
  • Partnership with Maintenance Efficiency Venture (MEV) accelerated adoption in global markets and underscored cost/safety benefits over hot work

Broad Material & Service Compatibility

Lokring supports a wide range of materials and service conditions:

  • 316L Stainless Steel (SS40): Ideal for corrosive environments; temperature de-rating up to 650 °F
  • MAS‑3000 (Microalloyed Carbon Steel): Durable for temperatures between −20 to 650 °F; suitable for select carbon steel pipes (ASTM A106, A53); caution in sour or caustic services
  • MAS‑3000‑RCPL (Stainless body + steel drive rings): Combines corrosion resistance with strength; avoid in sour gas and chloride-rich environments
  • LTCS‑333 (4130 Alloy Steel): Suitable for −50 to 800 °F; offers robust performance in high-temperature, high-pressure systems
  • Copper Nickel & Brass: CN‑200 and CN‑700 rated for a wide temperature/pressure range; also brass options for medical gas and vacuum applications

Optimal Sectors & Use-Cases

Lokring excels in:

  • Repair/retrofit of tight or hazardous environments (e.g., offshore platforms, refineries)
  • Environments where hot work is restricted or impossible (e.g., clean rooms, medical facilities)
  • Systems subject to vibration, thermal cycling, or corrosive exposure
  • Fast production setups or shutdown recoveries—minimal delays and rigorous reliability

Product Support

Did you know that Lokring has a global network of distributors?  Our team of authorized sales and service members can help answer questions you have about Lokring products or applications.

Find a Distributor

 

Pipe Solutions

Qualified to the requirements of the ASME B31 pressure piping codes for pressure and fatigue design, as well as materials of construction.

– See Pipe Products –

 

Tube Solutions

Extensive mechanical and environmental testing has demonstrated the sealing integrity of the Lokring connection in a wide range of applications.

– See Tube Products –

 

Medical Gas
Solutions

Technology for medical gas applications meets the requirements of NFPA 99: Health Care Facilities Code, 2012, 2015 an 2018 Editions.

– See Med Gas Products –

 

Marine Pipe & Tube Solutions

Our products are approved by ABS and NAVSEA for use in marine conditions with confidence.

– See Marine Products –

 

Railroad
Pipe Solutions

approved unconditionally by the American Association of Railroads for installation on interchange service freight cars since 1997.

– See Railroad Products –