Sealing devices

Labyrinth Seals The labyrinth is one of the simplest of the many sealing devices. It consists of a series of circumferential strips of met extending from the shaft or from the bore of the shaft housing to form a cascade of annular orifices. Labyrinth seal leakage is greater than that of clearance bushings, contact seals, or filmriding se s. 

Either trickle (flapper) or star (rotaiy) valves are effective sealing devices for solids discharge. Each functions with a head of sohds above it. Bottom of the bed discharge is also acceptable via a slide valve with a head of solids. 

Gaskets, packing, and sealing devices 3061 Molded, extruded, and lathecut mechanical rubber products... 

Hermetically sealed devices are devices sealed to prevent flammable gases from reaching enclosed sources of ignition. These devices are suitable for use in Division 2 and unclassified areas. 

Hermetically sealed electrical devices must be verified by a testing laboratory to meet mechanical abuse and to withstand aging and exposure to expected chemicals. Devices potted with common silicones and similar materials by an end user or even a manufacturer, without testing, and devices merely provided with O-rings seldom meet acceptable criteria. Normally, hermetically sealed devices must be sealed through metal-to-metal or glass-to-metal fusion. Many electrical relays, switches, and sensors are available as hermetically sealed devices for common oil and gas producing facility applications. Hermetically sealed devices are often desirable to protect electrical contacts from exposure to salt air and other contaminants. 

Hermetically Sealed. A hermetically sealed device shall be sealed against the entrance of an external atmosphere and the seal shall be made by fusion, e.g., soldering, brazing, welding, or the fusion of glass to metal. 

Note It is essential that lubricants are compatible with the materials used in the construction of machine tools, and particularly with sealing devices. 

Two sealing devices are described and discussed in this section packed stuffing boxes and simple mechanical seals. 

Figure D-3A—Piping for Throttle Bushings, Auxiliary Seal Devices, and Dual Seals—Plan 52...

Dual seals and anxiliary shaft sealing devices (see data sheets). ... 

Autosampler cup cap (used to seal device, both before and after use)... 

Leakless sealed cells and sealing device are now available from Seiko Instruments Inc. and Nippon Kayaku Co., Ltd. 

Hit the top of the cell and lid strongly with the pestle of the sealing device to seal it hermetically. 

---