Previously, says Ceetak, the use of radial shaft seams manufactured in elastomer compounds, in service conditions involving high levels of vacuum, has been virtually impossible. High radial forces cause eventual abrasion of the seal material, and high loss moments and high friction temperature cause additional problems. But the company says it has developed a range of rotary seals that can provide a solution to these problems, while reducing operating costs and improving reliability.
The VR seal uses a unique design that requires considerably less radial force to form an effective and integrated sealing face. As a result, material stresses are dramatically reduced, so increasing operating life while minimising maintenance and replacement costs.
In addition to these process benefits, the VR seal is available in a variety of materials to suit different applications, including NBR, FPM, HNBR, EPDM, silicone and VAMAC. Various industry approvals are also available, including materials to FDA standards. Depending on the shaft media, the front and back specifications of each seal can also be formed from a combination of materials to create specific operating characteristics.
Andrew Kownacki, Ceetak technical director, explains: "The VR rotary seal was developed over an 18 month period and we have succeeded in reducing the radial force in most applications to less than one third that of conventional rotary sealing components. By also incorporating a choice of materials to withstand various different media, we have created a range of products that can made a real difference in production processes."
