Fujikin Singapore has developed a line of products for various applications, from semiconductor, oil & gas, chemical & petrochemical, power plant & others (pulp & paper, marine, alternative energy and more), bio-pharma and food & beverage.

To extend Fujikin's services and offerings overseas, Carten Controls Ltd. (CCL), acquired in 1990, is an Irish precision valve company located in Waterford, Ireland and manufactures valves of sizes up to 12 inches and more for the global market. TK-Fujikin (TKF), acquired in 2009, is a South Korean manufacturer of valves, fittings and regulators that complements Fujikin's own line of products.

In this article, we will cover What is a Tube Fitting?

Tube Fitting

Tube fittings connect runs of tubing (for in-line, offset, multi-port, and mounting configurations) to other tubing sections, pipe, hose, or other components. Systems are typically configured with straight sections connected by fittings or specially formed connections and joints.

Fitting construction and material specifications are application-dependent; consulting the fitting supplier is typically a wise route for optimizing component selection. However, most tube fittings correspond to either hydraulic or pneumatic systems. The basic system type is the first step to determining the type of fittings right for the application.

• Hydraulic applications involve the transfer of liquid fluids such as water and other chemical solvents. Hydraulic fittings must have seals which prevent the leakage of liquid and often be resistant to rust or other possible chemical corrosion.
• Pneumatic applications involve the transfer of gases. Pneumatic fittings must have very tight seals to prevent gas leakage and must be resistant to chemical corrosion.
• Other applications such as structural design also incorporate tube fittings. These fittings must have strong physical integrity but typically do not require sealing because they do not carry fluids.

Types Of Tube Fittings

There are four primary styles of high to low pressure tube fittings. They are differentiated by their end connections and applications, each having its own advantages and disadvantages.

• Compression Fittings: Slide over the tube and use a ferrule design to coin and seal on the OD of the tube.
• Cone and Thread Fittings (C&T): Tube ends are coned (chamfered) and threaded. The threads allow for positive lock and sealing of the end face of tube to the fitting body.
• Butt Weld Fittings: Permanently joins to the tube end by welding the surrounding metal at the tube end with the fitting.
• Push-To-Connect Pneumatic Fittings: Instant connections just by pushing the tube into the fitting.

For most pressure applications (up to 15,000 PSI) fitting sizes are specified by the tubing OD (outside diameter); i.e. 1/4, 3/8, 1/2, 3/4 inch (6, 10, 12, 20 mm). Each style of fitting is available with the specified size end connections and in different configurations, such as straight, elbow, tee and cross.

Sometimes they are used as reducing fittings; for instance from a larger size connection such as 3/8 to a smaller, 1/4 tube. Many are also available with the designated style (i.e. compression) on one port to an alternative connection on another port, such as NPT or SAE thread, or male NPT to C&T and many other combinations.

Tube Fittings Size Chart

If you'd like to find out more and are looking for experienced professionals in the design and manufacturing industry, you may contact Fujikin Singapore at enquiry@fujikin.com.sg or at +65 6848 5760.