The structure of the fittings is basic, they have a nut, a rear ferrule, a front ferrule and a body; when installed it makes a five piece connection with the addition of a tube/tubing to provide leak-free connection.

The two ferrules remain securely around the tube without damaging the surface. Some studies have shown that the pipe will give way before the double ferrule joint begins to leak. The reason behind the effectiveness of this type of fitting lies in the two-ferrule configuration that incorporates geometry and metallurgy. All activity in the fitting is an axial movement along the tube rather than a rotary movement to make the joint. This axial movement prevents the transfer of any torque from fitting the tube.

Functionality of the Splints

The two-ferrule mechanical gripping design separates the tube sealing and clamping functions; Each splint is optimized for its function. The front ferrule creates a seal against the body of the fitting and on the outside diameter of the pipe. As the nut is turned, the rear ferrule axially advances the front ferrule and radially applies an effective tube grip.

Accessories Assembly

During fitting assembly, the front ferrule is driven into the fitting body and pipe to create primary seals, while the rear ferrule rotates inward to create a strong grip on the pipe. The rear ferrule geometry allows for a hinge-collar action that translates axial movement into a radial swaging action on the tube, but operates with a low assembly torque requirement.

Gas Tight Seal

Excellent sealing and constant reassembly help ensure accurate measurements of process parameters (air, steam, fuel and water) to maintain efficient operation in a plant. Additionally, the Inconel 625 tube fittings minimize fugitive emissions, as well as process fluid leaks and operating costs.

Vibration (Tube Grip)

Fittings provide excellent vibration fatigue resistance and tube support, even in harsh or stressful environments such as hydrocarbon processing, vehicle applications, or rotating equipment applications. The hinged clamping rear ferrule isolates and protects the increased stress that is generated along the tube during the clamping portion of the assembly. The clamping portion of the rear ferrule allows more material to come into contact with the tube. This pickup action improves gripping performance and provides both direct and axial support to the gripping function. This design minimizes the effects of bending and deflection at the pipe grip point.

Thermal shock

The dynamically loaded, two-sleeve elastic design compensates for temperature changes during system start-up and shutdown and helps eliminate leaks related to rapid thermal expansion or contraction.

Corrosion

Fittings are available in a variety of materials, including optimized 316 stainless steel chemistry with elevated levels of nickel, chromium and other elements for superior corrosion resistance in a variety of applications, including chemical processing, acid gases and underwater systems.

Applications

Stainless steel instrumentation Inconel 600 tube fittings are used for specialized applications in oil and gas facilities, steam and gas turbines, aerospace, defense, power generation, chemical processing, petrochemicals, alternative fuels, shipbuilding and medical equipment. These stainless steel instrumentation fittings are available in various types and grades, of which SS 304 instrumentation tube fittings and SS 316 instrumentation tube fittings are the two most widely used grades.