Metallic bellows

The implementation of high-pressure reaction cells in conjunction with UFIV surface science techniques allowed the first tme in situ postmortem studies of a heterogeneous catalytic reaction. These cells penult exposure of a sample to ambient pressures without any significant contamination of the UFIV enviromnent. The first such cell was internal to the main vacuum chamber and consisted of a metal bellows attached to a reactor cup [34]- The cup could be translated using a hydraulic piston to envelop the sample, sealing it from... 

Cryogenics Cryogenic liquids are too cold for most seals. Use a metal bellows mechanical seal with no elastomer parts. 

List three examples of the four components, e.g., a metal bellows pump. 

C) range, special metal bellows seals may be used up to the +650°F (343 °C) range. Low temperature (—100 °F to 0 °F) (—73 °C to —17 °C) also requires special arrangements, since most hydrocarbons have little lubricity in this range. 

In addition, an interesting phenomenon was observed when pumping the sample gas through the sampling probe. The chamber air is pulled through the screens and filter, and through a dry test meter with a Metal Bellows pump. When pump is on, a steadily increasing number of detectable condensation nuclei is found. 

Fig. 1. a) Linear correlation between metallicity, in the Carreta Gratton (1997) scale versus W . Triangles are the open clusters, open circles are the globular clusters and open stars are the data by [2]. b) Metallicity distribution for the field situated at 5° (dashed line) and 8° (solid line) from the bar. The amount of stars with metallicity bellow [Fe/H]=-1 increases at larger distances from the bar. 

The other two were connected in a circuit containing a bellows-type gas circulating pump (Metal Bellows Corp. Model MB-21) to a gas sampling valve mounted in a Carle AGC-311 gas chromatograph. The latter is equipped with two columns, Porapak (80 N, 20 Q,... 

Unless otherwise specified, the spring material for multiple spring seals shall be Hastelloy C. The spring material for single spring seals shall be austenitic stainless steel (AISI Standard Type 316 or equal). Other metal parts shall be austenitic stainless steel (AlSl Standard Type 316 or equal) or another corrosion resistant material suitable for the service, except that metal bellows, where used, shall be of the material recommended by the seal manufacturer for the service. Metal bellows shall have a corrosion rate of less than 50 jm (2 mils) per year. 

Fig. 2.17. The Krummenacher valve. A yoke, B spindle, C handle, D metal bellows, E ball-and-socket joint, F annular knife-edge, G annular trough filled with soft metal, H cylindrical heating elements fitting into cavities in the metal body A/, J sockets for Housekeeper seals.

A yoke A attached to a cylindrical body M carries a threaded spindle B operated by a handle C. It is attached to a metal bellows Z) by a ball-and-socket joint E. By this means the annular knife-edge Fean be thrust into the... 

Gas Samples for Subsequent Laboratory Analysis. Collection of air samples for later analysis in the laboratory is a common technique used for aircraft sampling. Whole air sampling for stable compounds (CO, CO , ha-locarbons, and low-molecular-weight hydrocarbons) is usually accomplished by filling a container to a pressure of about 2 atm (203 kPa) with a metal bellows pump. Alternatively, containers may be evacuated in the laboratory to a low pressure and filled during flight by simply opening a valve at the appropriate time. Containers are typically constructed of stainless steel that has been electropolished or treated in some way to reduce surface activity... 

The thin-wall bellows element should be designed for membrane stresses to conform to code-allowable stresses. The sum of membrane and secondary bending stresses should not exceed 1.5 times the yield stress in order to prevent the collapse of the corrugations caused by pressure. Bellows subjected to external pressure can be analyzed in a manner similar to a cylinder, utilizing an equivalent moment of inertia. The fatigue life can be estimated based on the sum of deflections and pressure stresses as compared to S/N curves based on bellows test data or using the curves in B31.3 Appendix X, Metal Bellows Expansion Joints. Formulas for the stress analysis of bellows are available in the Expansion Joints Manufacturing Association (EJMA) Standards (37). 

Fig. 5.3. Wayda-Dye greaseless vacuum line. This apparatus makes extensive use of metal bellows tubing and O-ring seals. Thus the reaction vessels, filters, and other items can be tilted and manipu lated like Schlenk ware, and high vacuum conditions can be achieved for the removal of atmospheric gases and for baking out residual moisture. Trap to-trap distillation of volatile solvents such as NH) or SO is readily accomplished with this apparatus. This version is not designed for the measurement of volatiles or trap-to-trap separation. (Reproduced from A.L. Way da and J. L. Dye, J. Chent. Educ. 62, 356 (1985) by permission of the copyright owner the Division of Chemical Education of the American Chemical Society.)...

Fig. 10.12(b). A metal bellows attached at one end to the body and at the other end to the stem forms a highly leak-tight but bulkier and more expensive seal. (Reproduced by permission of the copyright holder, Markad Services Co.)... 

Many kinds of flexible sample tubes have been devised. Four different kinds of sample containers are shown in Fig. 3. In all cases, either polyte-trafluoroethylene (PTFE) or metal bellows are used, and there is at least one threaded hole for withdrawal. For high-pressure reactions at temperatures of up to ca. 60 °C, several kinds of commercially available syringes and polyethylene tubes have also been used. 

Measurement with the Infrared Analyzer. The infrared analyzer was operated in the absorbance mode at 8.02 ym with a slit width of 1 mm, path length of 5.25 m, and response time of 1s. A closed recirculating loop containing a metal-bellows pump, a glass tee, and the infrared analyzer was assembled using low-volume tubing the total volume of the system was 5.64 L. 

Closed circulation maintained in system via a metal bellows pump... 

Figure 5.7 Three-dimensional drawing of the experimental system used to assess the catalytic properties of the amorphous iron silicate smokes. The (smoke) catalyst is contained in the bottom of a quartz finger (attached to a 2L Pyrex bulb) that can be heated to a controlled temperature. A Pyrex tube brings reactive gas to the bottom of the finger. The gas then passes through the catalyst into the upper reservoir of the bulb and flows through a copper tube at room temperature to a glass-walled observation cell (with ZnSe windows) in an P iiR spectrometer. From there, a closed-cycle metal bellows pump returns the sample via a second 2L bulb and the Pyrex tube to the bottom of the catalyst finger to start the cycle over again (Hill and Nuth 2003).

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