Viton seals

The electrochemical experiments were conducted in an apparatus consisting of an electrochemical cell attached directly to a UHV system and has been described in detail elsewhere (16). The transfer between UHV and the EC was accomplished via a stainless steel air lock vented with ultra-pure Ar. Differentially pumped sliding teflon seals provided the isolation between UHV and atmospheric pressure. The sample was mounted on a polished stainless steel rod around which the teflon seals were compressed. All valves in the air lock were stainless steel gate valves with viton seals. Details of the electrochemical cell and conditions are contained in reference 16. Electrochemical potentials are referred to a saturated calomel electrode (SCE). 

Multinuclear NMR spectroscopy is being used increasingly to study catalytic reactions. In order for such studies to be possible, all contact betv een the sample solutions and the metal part of the cell body has to be avoided because of possible catalytic effects. All materials in contact vith the sample solution have to be chemically inert and nonmetallic quartz, glass, PTFE, Vespel (polyimide polymer, Dupont de Nemours), PCTFE (poly-chlorotrifluoroethylene), Viton seals, etc. 

All measurements with EIS were performed in three-electrode compartments similar to the cell described in Ref. [81]. The coated substrates were transferred into a chamber with a relative humidity of 96% for 2 days before they were used as working electrodes. A Teflon body separated with a viton sealing ring was pressed on the samples to form the cell. The electrodes had an apparent surface area of... 

Table 8 shows results obtained on Viton seal compounds in the same fluids, at 200°C. Nitrile could not perform well at this temperature due to simple heat degradation. 

The molded liners for the inlet head, cylinder section, and conical sections have Integral molded gaskets for sealing at the flanged joints. Molded liners and vulcanized linings are offered in gum rubber, polyurethane, nitrile rubber, butyl. Neoprene , Viton , Hypalon , and other liner materials can be supplied. 

For both types of micro devices, a stainless steel frame was used as holder and Viton gaskets were applied for sealing ]72-74], A clear PMMA cover plate was also used and served for compression. This cover plate provided housing for a mini UV lamp used for irradiation. The detection imit was packaged in a similar fashion. Optical fibers were also integrated. 

Figure 2.39 (a) Schematic representation of the experimental arrangement for attenuated total reflection of infrared radiation in an electrochemical cell, (b) Schematic representation of the ATR cell design commonly employed in in situ 1R ATR experiments. SS = stainless steel cell body, usually coated with teflon P — Ge or Si prism WE = working electrode, evaporated or sputtered onto prism CE = platinum counter electrode RE = reference electrode T = teflon or viton O ring seals E = electrolyte. 

Mechanical seal materials For streams containing chlorides, all springs and other metal parts should be Alloy 20 or better. Buna N and Neoprene should not be used in any service containing aromatics. Viton should be used in services containing aromatics above 95° C (200° F). 

Figure 16. Flowcell reactor constructed from silica coated aluminium plates sealed with a viton spacer [35],...

The viscosity of the reaction mixture is now too high for the final polymerization to be carried out in the same apparatus . For laboratory purposes simple metal forms are sufficient.They consist of two metal plates covered with a Teflon film. A temperature-and chemicals-resistant hose (e.g., VITON A) serves as sealing and distance control.The whole set-up is pressed together with clamps until a distance of about 5 mm is reached. When filled with the hot prepolymerization mixture they are heated in a vacuum oven under nitrogen ( ) according to the following program ... 

Figure 1 is a sketch of a complete apparatus for the preparation of tetrachloro-diborane(4). Boron chlorides are very corrosive and attack many elastomers and vacuum greases, so only Teflon, Viton, and halocarbon greases should be used for seals and lubrication in the vacuum system. 

Figure 1. Exploded view of RO cell (to scale). The various components of the cell fit together, are compressed by machine bolts, and are sealed with Viton O-rings. The membrane (effective diameter = 3.8 cm) is compressed against a porous steel plate (1/16 in., porosity = 25 pm) and flushed with feed solution. A certain amount of water penetrates the membrane and is collected as the permeate water (D). The feed solution enters the cell (A) and washes across the membrane (B) before being forced out of the cell (C).

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