850

+ 30 / +125

3,560

area. Figure 44 represents an early tandem seal arrangement for this type of service. Applying this technology to pumps has resulted in a significant increase in equipment reliability. A list of typical applications for non-contacting gas seals to be applied to vaporizing hydrocarbon liquid services is shown in Table 2.

FIGURE 43 A safety gas panel for monitoring gas pressure and flow (John Crane Inc.)

Seal

FIGURE 45 A non-contacting gas-lubricated seal for cryogenic service (John Crane Inc.)

Cryogenic liquids represent a similar design challenge in sealing technology. Traditionally, pumps that are used to pump these liquids relied on contacting seal designs. Although these fluids were at cryogenic temperatures, the seals were operating near the boiling point of the liquid. Frictional heat was enough to vaporize or flash the liquid to a gas. This resulted in short seal life. By allowing the liquid to flash to a gas and by using non-contacting gas lubricated seals, seal life has been extended from weeks to years. A non-contacting gas lubricated cryogenic seal is illustrated in Figure 45. Due to the low temperatures involved, a metal bellows is required in the seal design.

Survival Treasure

Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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