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FK Series Medium-Pressure Tube Fittings

FK medium pressure tube fittings

FK Series Medium-Pressure Fittings and Adapters up to 22 500 psi (1551 bar)

Shop FK series Medium-Pressure Tube Fittings

FK Series CatalogFK Series Catalog — Alloys


Pressure Ratings Up to 22 500 psig (1551 bar)
Temperature Ratings Up to 1000°F (537°C)
Materials of construction 316 Stainless Steel, Super Duplex Alloy 2507, or Alloy 625
End Connections
Types NPT, medium-pressure cone and thread adapters, male SAE/MS
Sizes 1/4, 3/8, 1/2, 9/16, 3/4, 1 in.; 6, 10, 12 mm (1 in. only available in 316SS)
Configurations Straights, elbow, tees, cross, port connectors, tube adapters, caps, plugs
Other medium-pressure products available Medium-pressure ball valves, medium-pressure tubing

Owners and operators are under intense pressure to contain costs, ensure safety and environmental compliance, and optimize efficiency. From initial construction and commissioning through daily operations and maintenance, there is tremendous focus on reducing total lifecycle costs. This often necessitates finding innovative alternatives to traditional medium pressure fitting solutions.

FK series compression-style fittings can deliver significant benefits to topside asset owners and fabricators in the oil and gas space. They reduce installation time and lower assembly and maintenance costs, while providing a more reliable and robust connection resulting in increased uptime.

reduce installation cost

Reduce Installation Cost

  • Installs approximately 5x faster than cone and thread
  • Uses common tools and simple assembly methods with minimal training
  • Pre-assembled cartridge for rapid, error-proof assembly

improve uptime

Improve Uptime

  • Leak-free performance at startup
  • Reliable performance in dynamic systems (vibration)
  • Reduces unplanned maintenance for leaking fittings

boost safety and environmental compliance

Boost Safety and Environmental Compliance

  • No leaks = environmentally-friendly
  • Avoid non-compliance events and costs
  • Proven reliability with over 100,000 connections installed

For support on a specific application, contact your local sales and service center

Cone and Thread or FK Series Compression Tube Fittings?

Owners and operators of offshore assets are achieving significant savings by making a change in the type of fitting they are specifying for their medium-pressure fluid system applications. By switching from traditional cone and thread fittings (Figure 1) to innovative FK series compression tube fittings (Figure 2), assemblers have been able to complete fitting installations approximately five times faster, all while virtually eliminating rework needs during hydrotesting and acceptance test steps. In addition, following asset delivery, performance of FK series compression tube fittings is improving system reliability and reducing overall maintenance needs. These efficiencies deliver significant savings and a reduced total cost of ownership.

cone and thread fittings cross section
Figure 1: Review the details of the IPT Series design
FK fitting cross section
Figure 2: Review the details of the innovative FK series design

The key to these labor and cost savings is the reduced time required to assemble fittings used to connect tubing with system components. A cone and thread fitting, which requires the installer to prepare a piece of tubing, takes approximately five times longer to assemble compared to an FK series compression tube fitting. With dozens to hundreds of connections required on assets, the faster installation capabilities of FK series tube fittings yield significant time and cost reductions, as well as accelerated deliveries of completed assets.

Watch and compare installation of FK series and cone and thread fittings

The simple two-piece design of the Swagelok patented FK series medium-pressure tube fittings consists of a female fitting body and preassembled cartridge containing the male FK series nut and front and back ferrules on a disposable plastic arbor. The preassembled cartridge ensures installers correct ferrule orientation, visual confirmation of ferrule presence, and easy and proper installation into the female body. The Swagelok FK series medium-pressure tube fitting offers a leak-tight gas seal and vibration resistance in applications up to 22 500 psig (1551 bar). Available in 316 stainless steel, super duplex alloy 2507, or alloy 625 material.

FK medium pressure tube fittings

Shop Medium-Pressure, Gaugeable Tube Fittings and Adapter Fittings (FK Series) Browse our Catalogs

Questions? Locate a sales and service center

Safe Product Selection: The complete catalog contents must be reviewed to ensure that the system designer and user make a safe product selection. When selecting products, the total system design must be considered to ensure safe, trouble-free performance. Function, material compatibility, adequate ratings, proper installation, operation, and maintenance are the responsibilities of the system designer and user.

⚠ Warning: Do not mix/interchange Swagelok products or components not governed by industrial design standards, including Swagelok tube fitting end connections, with those of other manufacturers.

For applications below 10 000 psi, consider Swagelok Tube Fittings