Kalrez O-ring

Figure 3.3 Side- and top-view of the in situ infrared autoclave. A IR window B Turbine rotor C Reagent addition D Thermocouple E Opening between upper and lower chamber F Electrical heaters C Kalrez O-rings (from Ref [6], reproduced by permission of Elsevier).

All connections between the different components of the reactor are sealed with 6 373 Kalrez O-rings. The associated instrumentation is composed of a set of 10 K-type thermocouples and a pressure gauge using a tantalum membrane. 

The heat of adsorption of water vapor onto the surface of both polymorphs of the drug was measured under different RH conditions using an isothermal heat conduction microcalorimeter (Thermal Activity Monitor, TAM, Thermometric AB, Sweden). The integral heats of adsorption were measured using a TAM instrument fitted with a Thermometric RH perfusion ampoule (accessory Model 2255) adapted with Kalrez O-rings. The RH above the solid samples was controlled as originally described by Bakri (1993)... 

Kalrez O-rings are available from Service Seal and Packing, Inc., 277 Fairfield Road, Fairfield, NJ 07006 (201-575-4277) Size Oil (Kontes 8 mm valve seat size), 15.80. Size 116 (15 mm 0-ring joint size), 27.90. 

Mating Ring Tungsten Carbide, Silieon Carbide Primary Ring Carbon, Silieon Carbide O-Rings Elastomers (Viton, Kalrez )... 

At the request of an international petroleum company, a major manufacturer and supplier of down-hole equipment performed tests of the various elastomers commonly used in the construction of packers and other oil field tools. Seven of the nine most commonly used thermoplastic materials were found to be completely inert to TKPP solutions. The test included continual immersion in saturated TKPP for 21 days at 280°F. Only two elastomers, Vi-ton and Fluorel, showed any adverse reaction. O-rings made from these two elastomers showed minor cracking at the termination of the test. A listing of the elastomers that tested inert to TKPP solutions include nitrile, saturated nitrile (HNBR), Aflas, Kalrez, PEEK, Glass-filled Teflon, and Ryton. Several of these elastomers are attacked or degraded by conventional clear completion fluids containing calcium and zinc halides. The inertness of commonly employed elastomers to TKPP is an important advantage for TKPP fluids in normal operations. 

A fluoroelastomer manufactured by Du Pont called Kalrez, has mechanical properties and resistance to oxidants which are similar to those of Viton. In contrast with Viton, Kalrez has good resistance to polar molecules such as amines, ethers, ketones, and esters. Kalrez is unique among the elastomers in its tolerance to both polar and nonpolar solvents. The cost of O-rings made from Kalrez is very high, but for certain critical applications this cost can be justified because of the outstanding range of solvent tolerance. 

AKP-30 supports were prepared as described in chapter 4. After firing the supports were machined to the required dimensions and polished until a shiny surface was obtained. For low temperature measurements, up to 300°C, the supports were used without any further sealing. The membranes were sealed with Kalrez or PTFE O-rings in a K250 testing cell. For the... 

In practice, only the seat 0-ring of the "Flickit" valve is replaced with Kalrez. Other valves use Teflon plugs without a seat 0-ring and are backed by Viton 0-rings. Since Kalrez does not have the resiliency of Viton, the "Flickit" valve O-ring seat should be inspected periodically to ensure that its shape (and the seal) have been retained. 

O-ring seals are less common in HPLC columns, but are quite feanUe. The main issue is the compatibility of the O-ring material with the mobile phase. Incompatible O-rings can disintegrate resulting in a sudden loss of the seal O-rings made of fluorocarbon-based rubbers such as Kalrez or Chemraz have a suffidently broad solvent compatibility to be useful with all molnle phases commonly used in HPLC. 

Perfluoroelastomer (tetrafluoro-perfluoro-methyl vinyl ether co-polymer) n. Introduced by DuPont in 1977 as Kalrez , this elastomer combines the properties of a conventional fluoroelastomer, such as vinyhdene fluoride-hexafluoropropylene co-polymer, with those of a fluorocarbon resin such as polytetrafluoroethylene. It has found application for O-rings and seals that must withstand strong chemicals and solvents at high temperatures. 

The traditional advantage of a probe optic employing O-rings, such as Kalrez and Viton , is that these materials are more inert in some corrosive environments than most brazing materials (the newer braze alloys mentioned being the exception). Because the O-... 

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