If fittings do not make leak-tight seals, the system will not perform properly, no matter how expensive or sophisticated an analytical system's valves, columns, detectors, or integrators might be. The fittings must also be inert relative to the sample components, provide a flow path which does not induce any turbulence or mixing, and add as little volume as possible to the system.
Fitting designs which best address the aspect of added volume allow the tube ends to butt directly to each other or have bores which match the tubing bore, leaving no dead or unswept volume. Such fittings are called zero dead volume fittings.
The basic building block is the two piece compression fitting, in which a ferrule is compressed onto the tube as a nut is tightened offering reliability in high pressure situations and in connecting metal tubing.
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Cheminert fittings are ideally suited for applications requiring an inert, biocompatible, metal-free flowpath. Wetted materials are PFA, FEP, CTFE, or PEEK, and uniform flow passages minimize mixing. All connections have zero dead volume.
High pressure Cheminert fittings
The Cheminert line of high pressure fittings is rated at 5000 psi with fingertight nuts, well beyond the burst strength of most PEEK tubing.
Low pressure Cheminert fittings
Cheminert low pressure fittings are ideally suited for flow injection analysis, low pressure liquid chromatography, and stream sampling devices. They may be safely used at pressures up to 500 psi and temperatures to 50°C.