Grayloc® Product Lines

We deliver industry-leading solutions for connecting critical service piping and vessel systems.

Oceaneering® Grayloc® product lines use innovative pressure-containing technologies to meet your operational requirements.

Grayloc® Clamp Connectors

Our field-proven Grayloc® clamp connectors have been used in a wide range of industries since the 1950s. The connectors are lighter, smaller, faster to make and break, and easier to maintain than conventional flanges. Stringent engineering processes and quality standards result in unparalleled and repeatable reliability.

Design Technology

  • Grayloc® metal-to-metal seal 
  • Self-energized and pressure-enhanced seal
  • Two-piece, four-bolt clamp design
  • Primary load-retaining member is the clamp, not the bolting
  • Significant space- and weight-saving design
  • Low makeup bolt torque
  • Visual indication of proper assembly
  • Reusable seal rings


  • Eliminates fugitive emissions with zero-leakage seal (10-6 atm cc/s helium)
  • Reduces installation time with only four bolts and 360° clamp rotation
  • Simplifies fabrication (no bolt holes to align)
  • Lowers maintenance costs
  • Minimizes spare parts inventory
  • Enables design of lightweight and compact piping systems, using integral fitting configurations
  • Grayloc hub profiles can be integrated into third-party (OEM) products

Grayloc® Compact Flanges

Grayloc® compact flanges (GCFs) incorporate our proven metal-to-metal technology into a bolted flange design. Including the Grayloc seal ring in a compact flange design provides a solution with significant space and weight savings that outperforms conventional flanges.

Design Technology

  • Grayloc® metal-to-metal seal
  • Self-energized and pressure-enhanced seal
  • Space and weight are less when compared to conventional flanges
  • Optimized bolting configurations
  • Engineered to industry standard design codes, including ASME and API
  • Visual indication of proper assembly
  • Reusable seal rings


  • Eliminates fugitive emissions with zero leakage seal (10-6 atm cc/s helium)
  • Enables significant space and weight savings
  • Reduces installation time with smaller and fewer bolts
  • Lowers maintenance cost
  • Minimizes spare parts inventory
  • Eliminates mismatches common in male and female designs with standard seal interfaces
  • Enables design of lightweight and compact piping systems using integral fitting configurations
  • Enables integrating Grayloc hub profiles into third-party (OEM) products

Grayloc® Remotely Operated Connectors

Our field-proven mechanical Grayloc® remotely operated connectors are used in hazardous environments, personnel restricted areas, and automated operations. Developed in the 1960s for nuclear power operation, these connectors are recognized as industry leaders for remote and quick-opening applications.

Design Technology

  • Grayloc® metal-to-metal seal
  • Simple, reliable trunnion and screw mechanism
  • Single-drive screw adaptable to power drives
  • Self-supporting base plate
  • Retained seal ring also available with test ports
  • Suitable for manual operation
  • Unitized design


  • Eliminates fugitive emissions with zero leakage seal (10-6 atm cc/s helium)
  • Reduces risk and increases operational safety
  • Supports diver and/or remotely operated vehicle (ROV) installation, testing, and retrieval
  • Allows for manual override if power source fails
  • Reduces make and break time
  • Compatible with existing hydraulic, pneumatic, and electric power units
  • Lowers maintenance cost
  • Oil&Gas

    Subsea oil and
    gas production

    • Rigid and flexible flowline connections
    • Diver and/or ROV installation, testing, and retrieval
    • Field-proven in extreme conditions of North Sea applications
  • Factory Dk 01

    Petrochemical and refining

    • Inlet feed line connectors
    • Reliable in applications requiring frequent assembly/disassembly
  • Science 01

    Research and development

    • Quick-opening closures for laboratory pressure vessels
    • Ideally suited for high-pressure and high-temperature testing
  • Nuclear Dkblue 01


    • Initially developed for mechanical joints handling radioactive materials
    • Typically integrated in isolated hot-cell environments
    • Proven application for personnel safety

  • Aerospace

    • Launch pad fueling operations
    • Frequently accessed connections in test stands

Grayloc® Closure Systems

Grayloc® closure systems incorporate the field-proven design features used in Grayloc connectors, and can be supplied with safety interlocks and hinge and clamp hanger support systems.

Design Technology

  • Grayloc® metal-to-metal seal
  • Clamp hanger assemblies
  • Vertical- or horizontal-mounted, field-adjustable hinged door
  • Full ASME compliance with Section VIII Division 1, 2, and 3 code stamp capability
  • Safety interlock system options
  • Seal ring retention system
  • Available in horizontal and vertical arrangements
  • Compatible with hydraulic, pneumatic, and electric actuators


  • Eliminates fugitive emissions with zero leakage seal (10-6 atm cc/s helium)
  • Reduces risk and increases operation safety
  • Opens/closes quickly with only a single operator and no mechanical lifting
  • Engineered for design pressures ranging from full vacuum to 48,000 psi
  • Lowers maintenance cost
  • Minimizes spare parts inventory
  • Oil&Gas

    Oil and
    gas production
    Pig launchers and receivers (both topside and subsea)

  • ChemicalPlanht 01

    Oil refineries and petrochemical
    Reactor manways and large-diameter vessel closures

  • Science 01

    Research and development
    Frequently accessed vessel applications

  • Environmental
    Waste disposal systems

Non-Slam Nozzle Check Valves

Our field-proven non-slam nozzle check valves feature an innovative, maintenance-free, low-pressure-loss design that incorporates a unique, dual-spring closing action to provide a fast, dynamic response.

Design Technology

  • Tight shut-off, metal-to-metal seal
  • Unique dual-spring design for fast, dynamic response
  • All-metal assembly (no elastomers)
  • ASME Class 150 through to 4,500 and up to API 10,000
  • Industry-standard end connections available, including Grayloc hubs and compact flanges
  • Sizes from 2 in to 60 in with a wide variety of body and trim materials


  • Prevents return flow and water hammer with fast dynamic response
  • Optimized for low pressure loss
  • Maintenance-free design
  • Suitable for installation in any orientation (horizontal, vertical up or down, and diagonal)
  • Sized to eliminate disc chatter in low-flow conditions
  • Available from inventory, and expedited delivery can be accommodated

Universal Ball Joints

Our universal ball joints compensate for movement of piping and equipment while maintaining sealing integrity and relieving piping stresses. We provide reliable, serviceable, dynamic pipe connections suitable for use in steam, industrial, petrochemical, and marine applications.

Design Technology

  • 360° continuous rotation and up to 30° axial pivot
  • Low-break torque limits stresses on adjoining pipe
  • Reliable high-temperature, high-pressure graphite seal
  • Field injection port supports simplified, tool-free, in-line maintenance
  • Compact, lightweight design delivered pre-assembled with butt weld ends or flanges


  • Suitable for dynamic and static applications
  • Enables linear, rotational, or combined pipe movements
  • Compensates for thermal expansion, misalignment, and shifting equipment
  • Trusted in extreme and critical applications
  • Pre-torqued, hydrostatically tested and shipped ready for service
  • Fabricated, assembled, and tested expansion arm piping spools available
  • Available from inventory, and expedited delivery can be accommodated
  • Oil Barrel 01

    Steam assisted gravity drainage (SAGD), cyclic steam stimulation (CSS)

  • Marine2 Dk 01

    Ship loading and unloading

  • ChemicalPlanht 01

    Petrochemical and Refining
    Relief of pipe stresses due to thermal expansion

  • Power
    Solar panel arrays

We offer a vast portfolio of products that deliver the solutions you need to complete operations. 

  • ASME code-stamped pressure vessels
  • R-CON connectors
  • Swing bolt clamps
  • Orifice connections
  • Thermowells
  • Pulling heads
  • Slimline clamps
  • Extreme service connectors
  • Insulated connectors
  • Jacket connectors
  • Metal seal rings (½ in to 82 in)
  • Adapters and crossovers
  • Socket weld hubs
  • Threaded hubs
  • Flowline filters
  • Elbows, tees, and crosses
Contact Us | Grayloc Technology

Company page Since our founding in the early 1960s, Oceaneering has expanded and grown globally to service several industries such as the offshore energy industry, defense, entertainment, material handling, aerospace, science, and renewable energy industries. In 1964, Mike Hughes and Johnny Johnson formed a Gulf of Mexico diving company called World Wide Divers. The company grew in response to increasing demand for their services and in 1969 merged with two other diving companies to form Oceaneering International, Inc. To solve the toughest challenges, we do things differently, creatively, and smarter. As your trusted partner, our unmatched experience and truly innovative portfolio of technologies and solutions give us the flexibility to adapt and evolve, regardless of market conditions. Our mission is to solve the unsolvable. We thrive by creating industry-changing technically creative solutions for the most complex operational challenges under water, on land, and in space. Our five core values establish a common culture and demonstrate what is most important for us as a company. Since the beginning, the company has transformed from a small regional diving company into a global provider of engineered products and services. Today, we develop products and services for use throughout the lifecycle of an offshore oilfield, from drilling to decommissioning. We operate the world's premier fleet of work class ROVs. Additionally, we are a leader in offshore oilfield maintenance services, umbilicals, subsea hardware, and tooling. We also serve the aerospace, defense, and theme park industries. Underpinning everything we do, safety is not only the foundation of our core values, but it is vital to our unmatched performance record and company culture. The industries we serve are as diverse as they are complex. Whether we are engineering deepwater umbilicals or developing robotics for aerospace applications, the safety and health of our employees, vendors, and customers is an integral part of our day-to-day business. If we are working, then our responsibility is to be working safely. Since our inception in 1964, we have placed a high value on employee safety—from diving services and subsea inspection to vessel-based installation operations. We have and will continue to evolve not only our health, safety, and environmental (HSE) processes, but those of the industries in which we work. Although we have been fatality-free since 1999, our HSE journey goes beyond statistics. As our portfolio of services has grown, we have continued to prioritize and advance our approach to HSE.