Dynamic Testing For Dry Gas Seal With High Speed 15000 rpm
Dry gas seals are non-contacting, dry-running mechanical face seals that consist of a mating (rotating) ring and a primary (stationary) ring. When operating, lifting geometry in the rotating ring generates a fluid-dynamic lifting force causing the stationary ring to separate and create a gap between the two rings. Dry gas mechanical seals are mechanical seals but use other chemicals and functions so that they do not contaminate a process. These seals are typically used in a harsh working environment such as oil exploration, extraction and refining, petrochemical industries, gas transmission and chemical processing.
Machined-in lift profiles on one side of the seal face direct gas inward toward an extremely flat portion of the face. The gas that is flowing across the face generates a pressure that maintains a minute gap between the faces, optimizing fluid film stiffness and providing the highest possible degree of protection against face contact. The seal's film stiffness compensates for varying operations by adjusting gap and pressure to maintain stability.
In the dynamic condition, the progressively shallow spiral grooves draw the sealed gas toward the center dam and create gas film pressure to separate the faces so they become noncontacting during running. Special geometry of the spiral grooves provides a uniform hydrostatic and hydrodynamic pressure distribution and maintains the proper seal face gap for gas film stiffness. These features assist in quick liftoff, even during low-speed operation (10 fps [3.05 m/s]) for pressures less than 50 psig (345 kPa guage) and allow the seal faces to adjust rapidly to the changes in the process conditions.
Depending on the shape of the circumferential grooves, the seals can be unidirectional (Figure 1) or bidirectional (Figure 2). A bidirectional seal provides protection from reverse rotation in situations such as the failure of dis- charge check valve and eliminates the need for spare seal cartridges on each end of a between-bearings centrifugal compressor. The spare seal cartridge can be installed at either end of the compressor. A sealing dam and land are shown in Figures 1 and 2. Figure 3 illustrates the pressure profile across dry gas seal faces during dynamic condition.
Who can make such dry gas seal in china?
as we all know, dry gas seal is a complicated mechanical seal, and need really high technology for mechanical seal, so just few factory can make such dry gas seal in china.
Lepu seal is one of them who can make such high technology dry gas seal, we install a special laboratary and production line for this dry gas mechanical seal, and can provide dry gas seal include FLOWESERVE, JOHN CRANE, BURGMANN brand dry gas seal. so if any one looking for dry gas seal, lepuseal may be the best choice.