Valco zero volume ferrules may be used with all Valco fittings and with those of most other manufacturers. Valco metal ferrules cut a ring near the end of the tube, preventing tube release at high pressures without significantly deforming and restricting the tube interior. (However, if the hardness of the tubing is equal to or greater than that of the ferrule, deformation of the tube rather than a cut ring is likely.)

Make up usually takes only about a 1/4 turn beyond the point where the ferrule first starts to grab the tubing. The maximum pressure limit is generally determined by the yield strength of the tubing. The exception is for very narrow bore Type 316 stainless steel tubing, where the maximum operational limit of Valco ferrules and fittings is 10,000 psi, regardless of the tubing strength. The maximum pressure for brass is lower, and depends on the tubing used. If you have questions about a particular tubing/ferrule combination, consult our technical staff.