Sealing elements

Shaft-sealing elements can be split up into two groups. The first type may be called pusher-type seals and includes the 0-ring, V-ring, U-cup, and wedge configurations. Figure 10-116 shows some typic pusher-type seals. The second type is the bellow-type seals, which differ from the pusher-type seals in that they form a static seal between themselves and the shaft. 

Figure 13-29. Various types of shaft sealing elements.

The rectangular element valve, as the name implies, uses rectangular-shaped sealing elements. These valves are the feather valve, channel valve, and the reed valve. These valves are applied to the industrial air machines for the most part. A channel valve is shown in Figure 3-10. 

The poppet valve (see Figure 3-13) consists of multiple, same-size ports and sealing elements. The advantage of the valve is that has a high flow efficiency due to the high lift used and the streamlined shape of the sealing element. The disadvantage is that the valve is not tolerant of... 

Index of Relative Leakages for Single-Sealing Elements... 

Ceramics are highly resistant to wear, chemical attack and high temperatures and, consequently, have many applications. They are frequently bonded to metal in making seal components or applied as a coating for shafts where seal elements introduce wear. 

Excessive radial movement can cause wear, fretting, or pitting of the shaft packing or secondary sealing element at the point of contact between the shaft packing and the shaft or sleeve OD. 

Shaft 2, Seal element 3, Cooling 4, Three-piece segmented ring 5, Six-piece semented ring 6, Support ring. 

To permit a leakproof and secure connection between equipment and the PVDF tubes a special type of fitting was developed and tested, see Figure 6. This fitting uses a cone of PTFE as a primary sealing element. To ensure a fairly constant pressure on the... 

Siemens Concept (Fig. 16). The planar concept of SOFC developed by Siemens is similar to the sandwich structure of the PEM single cell (see Fig. 6). A foil of YSZ with a thickness of 150-200 pm acts as the supporting component on which the electrode materials are deposited the single cells are then stacked with interconnectors with the gas channels and sealing elements in between. The gases can be supplied in co-, cross-, or counterflow and can be let to and out of the stack in internal or external... 

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