Type 28XP
Manufacturer: John Crane

Non contacting Gas Seal for Turbo Compressors
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.
• Unidirectional or bidirectional capability
• Single, double opposed or tandem configuration
• Robust design with unparalleled field proven pedigree
TEMPERATURE LIMITS220°F to 600°F/ 140°C to 315°C, dependent on overall duty condition
PRESSURE LIMITS6,500 psi(g)/450 bar(g) across single stage
SPEED LIMITS660fps/200m/s
SIZE LIMITS13.75"/350mm