Make Working in a Space Restricted Area Easier
When installing equipment and making tube runs, the traditional Swagelok Tube Fitting requires axial clearance to pull the tubing out of the fitting. As an example a ½” Swagelok tube fitting, model SS-810-1-8, requires an insertion depth of 0.90”. So, to remove the tubing from the fitting you need to be able to pull the tubing back 0.90”. On many applications, this is no problem and plenty of room is available axially. If that space is tight you can bend two 90° bends and use elbows (see drawing right).
Another frequently encountered installation problem is item maintenance. A piece of equipment must be removed physically from service for proper maintenance. This involves uninstalling the equipment from the tubing run. If there is not axial room to pull back the tubing from the fitting, an easy job like a filter change, can end up taking all day.
Swagelok makes two families of fittings which require zero clearance to remove the tubing from the fitting body. Swagelok’s VCO o-ring sealed and VCR gasket sealed fittings are zero clearance fittings. Zero clearance fittings do not require axial clearance to remove the tubing from the fitting. Loosen the female nut and the device lifts right out.
The VCO Fitting utilizes an o-ring which seals against a mating smooth gland face (see drawing above). When the nut is tightened ⅛th turn from finger tight, a seal is made which can withstand full vacuum to several thousand psi. Actual pressure rating is dependent on sizes. Consult the VCO® O-Ring Face Seal Fitting catalog. Pressure rating is based on ASME Code for Pressure Piping B31.3 Process Piping and B31.1, Power Piping. The standard materials are 316 Stainless Steel and Fluorocarbon FKM o-rings, although other alloys and o-rings are available. A wide variety of shapes and sizes from ⅛” through 1” are available. Temperature is o-ring dependent. The VCR Fitting seals on a gasket, captured between two beads. Standard fitting material is 316L Var (Swagelok designator 6LV) or 316. Standard gasket materials are Nickel, Copper and 316 stainless steel, although other materials are available. Temperatures up to 1000°F may be seen, depending on material selected. Pressure ratings are dependent on fitting size and shape and are shown in the VCR® Metal Gasket Face Seal Fittings catalog. Pressure rating is based on ASME Code for Pressure Piping B31.3 Process Piping and B31.1, Power Piping.