Automatic vee packing has been around since the 1920’s, when duck-and-rubber tubing was used to seal steam engines. Over the years, its use has expanded to seal plungers and rod and piston bores in a wide range of hydraulic applications in industries as diverse as automotive, pressing and forming, steel, off highway, mining, nuclear, oil and gas, food processing, pharmaceuticals and chemical production.
The multiple hinge-lip design has the advantage of creating a strong, tight seal that is capable of reacting to small changes in pressure, maintaining a low-pressure seal even in vertical applications, and sealing high pressures, as well as providing an immediate sealing reaction to pressure spikes and overloads. This is why many people refer to it as automatic packing.
One of the major disadvantages of rubber fabric seals, in general, has always been that as it absorbs fluid, the material will soften and relax its load and will need to be re-energized. In days gone by, this was done by regular axial loading via the gland follower, and the practice of tightening the gland nuts was at one time a regular Friday afternoon maintenance job. This issue has been addressed in many ways over the years: spring loading the male adaptor; spring loading the gland follower; making the male adaptor a U-Cup; and, finally, with the advent of machined seals, the very effective pre-energized seal design.
Pre-energized vee packing has drastically extended seal service life, and has also drastically increased the material options available to offer better seal/fluid compatibility.
This left the other major disadvantage: the seal’s ability to create a strong, tight seal capable of reacting to small changes in pressure caused the seal to also experience high friction.
Our engineering team has now developed a seal design that incorporates a low-friction feature on the dynamic surface of each seal lip which reduces dynamic friction while maintaining the unique sealability of vee packing. As with all of American High Performance Seals’ vee packings, this design is pre-energized.
This new design, the R1012LF for rods and plungers and the P1012LF for bore sealing, is available in a wide range of materials. These materials include polyurethane, Nbr, H-Nbr, Viton®, PTFE, etc., as well as our proprietary materials for industry-specific applications, such as metal-detectable materials, FDA-compliant materials, and nuclear service materials.
The seal design is also available in both split and solid versions all the way up to Ultra Large Diameters (25ft +).
Want to Learn More About Automatic Vee Packing and Other Seal Design Customizations?
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