Type 28XP: Possibly the most popular seal in the range today, the Type 28XP builds on the 28AT design and seals medium to high pressures with improved chemical resistance. It can also operate over a wider temperature range and is increasingly the preferred product for large sizes, and for applications requiring slow roll and coast-down conditions. Type 28 compressor dry-running gas seals have been the industry standard since early 1970 for gas-handling turbomachinery. Utilizing John Crane’s patented spiral groove pattern, these seals are non-contacting in operation. During dynamic operation, the mating ring/seat and primary ring/face maintain a sealing gap of approximately 0.0002"/5 microns, thereby eliminating wear. These seals eliminate seal oil contamination and reduce maintenance costs and downtime. Single, tandem and double seal arrangements are available.
Find out about Aura™; the next generation of gas seals from John Crane >