Tube Specification and Ordering
General Comments and Suggestions
Careful selection, specification, purchase, and handling of tubing are essential to the successful use of Swagelok tube fittings.
Several general rules apply:
- Metal tubing must always be softer than the fitting material. For example, stainless steel tubing should never be used with brass fittings.
- When tubing and fitting are made of the same material, the tubing must be fully annealed. Mechanical, structural, or ornamental grade tubing should never be used for fluid systems.
- Extremely soft or pliable tubing such as Tygon® or unplasticized PVC tubing should always use an insert. Seals on the outside diameter (OD) of tubing require a certain amount of tube resistance for tight sealing.
- Extremes of wall thickness should be checked against our suggested minimum and maximum wall thickness limitations.
- Swagelok tube fittings are not recommended for tube wall thicknesses outside the ranges shown in the following tables for each size. A wall too thin will collapse under ferrule action and may not resist enough to allow the ferrules to coin out surface defects.A wall thickness greater than the maximum suggested does not increase the allowable working pressure.
- Tubing surface finish is very important to proper sealing. Tubing that is deeply embossed (such as copper water tube); has a visible weld seam on its OD; or has flat spots, scratches, or draw marks may not seal properly when used with a fitting sealing on the tubing OD.
- Oval tubing that will not easily fit into fitting nuts, ferrules, and bodies should never be forced into the fitting. Such forced tube entry will scrape the tube OD surface at the maximum diameter, making sealing difficult.
- Laminated or multiwall tubing, such as braided hose, should generally not be used with Swagelok tube fittings. Because the Swagelok fitting seals on the tube OD, system fluid may leak between hose or tube layers, causing ballooning and possible wall rupture.
Need more Information or looking for a specific product?
Just fill in the below form and we will come back at the earliest