New universal seal from John Crane

John Crane, a leading supplier of engineered sealing systems and associated products, has launched a heavy-duty gas-lubricated universal seal, ideal for use in a wide variety of mixing and agitating equipment, as well as other top entry mixer applications.

With a modular cartridge design, the Type 7800 allows for maximum interchangeability and efficiency. Its convertible format supports contacting dry, contacting wet, non-contacting or a combination of non-contacting and dry contacting seal technology, without the need to change any adaptive hardware.

The seal also features a patented grooved rotor that allows equal lift in the presence of up to 0.125-inch radial run-out, while the primary ring shape responds under pressure, further enhancing very low speed face separation. Lift-off and the double cartridge uses common springs, allowing for seal-adjustment to axial motion; and the optimized drive minimizes seal face to seal cartridge hardware interaction, thereby eliminating low speed hang-up.

Mike Kalodimos, chemical market sector manager at John Crane, said that the Type 7800 was created specifically in response to the needs of the market-place: 'utilizing our extensive engineering capabilities and Solid Edge CAD-CAM, we partnered with all stakeholders - from marketing to engineering, quality and manufacturing - to bring this unique product to market.

'Conventional seals wear and therefore deposit debris in the vessel. However, through the elimination of seal lubrication liquid, the Type 7800 series can be configured to avoid wear and debris, equating to zero potential for batch contamination,' he added.

The company says that two patents are pending for the product: one for a special placement of spiral grooves on the element that establishes the balance diameter, and the other for a special pressure responsive primary ring shape.

To meet the needs of a variety of applications, the Type 7800 is available in two formats, as the Type 7828G and the Type 7828GD