TPi November 2019

Fittings, valves, flanges & connectors

PAEK polymer fitting for use in high-pressure liquid chromatography systems

If the carbon-fibre reinforced Victrex HT fittings are tightened with an appropriate tool, they are suitable for significantlyhigherpressuresof up to 1,000 bars (14,500 psi), confirmed Dr Andre Hütz, product manager at VICI AG International, based upon testing the company has performed.

VICI AG International, a manufacturer of valves and fittings for analytical, biomedical and biocompatible preci- sion instruments, is the first company to offer a new one-piece fitting using Victrex™ PAEK high-performance polymer. According to VICI, the injection-mould- ed Victrex HT™ fitting can withstand the high pressures inherent in liquid chromatography systems. The pressures required in liquid chromatography have been rising steadily for more than five years, given that the particles of the separation materials (usually modified silica gels) now frequently have a grain size of two micrometres or less. Consequently, substances within mixtures can be separated more quickly, with identical efficiency. To satisfy these demands, VICI has introduced a new one-piece fitting made from Victrex HT high-performance polymer, capable of withstanding pressures when tightened by hand of up to 500 bars (7,250 psi). By way of comparison, 350 bars (5,000 psi) was the limit for conventional PEEK fittings.

© VICI

Multi-use Victrex HT fitting for high-pressure range

This extra strength extends the service life of the fitting and allows several cycles of tightening and loosening of the fitting. In the past, this has only been possible in the high-pressure range using conventional two-piece ‘nut and ferrule’ fittings or complicated one- piece fittings. The VICI Group has designed and produced standard and customised metal and polymer valves and screwed connections for more than 50 years. The products are used in chromatography and in the analytical, biochemistry and medical technology fields. VICI AG International – Switzerland

Such higher pressures occur between pump and column in ultra-high performance liquid chromatography systems (UHPLC) and require that the stainless steel connecting capillaries used for the high-pressure range are fastened with appropriate fittings. Many UHPLC applications are carried out in a pressure range of approximately 600 to 800 bars, which means that the steel capillaries used between pump and column must use this type of fitting to provide a pressure-tight connection between system components. The greater strength of Victrex HT poly- mer compared to unreinforced PEEK prevents the fitting from breaking apart when it is being tightened, since the carbon fibres are aligned in parallel by the injection process.

www.vici.com Victrex – UK www.victrex.com

Blacoh receives US patent on hybrid valve

fluid flow. When put in series with a pulsation dampener, the flow improves significantly but, according to Blacoh performance tests, results cannot match the performance of the single construction Hybrid Valve for the steadiest flow. As a single unit, the Hybrid Valve takes up less space and has fewer leak points for improved functionality and lower maintenance costs. Blacoh Industries – USA

Blacoh Fluid Control, a specialist in pulsation dampening and fluid control equipment, has received US Patent 10,353,409 for its Hybrid Valve™, a combination pulsation dampener and back pressure valve. The Blacoh Hybrid Valve combines the steady flow control of a pulsation dampener and the regulation of a back pressure valve to deliver the performance and functionality of both in a single piece of equipment. In a metering pump system, using a back pressure valve alone does nothing to improve

sales@blacoh.com www.blacoh.com

Blacoh’s Hybrid Valve

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November 2019 TUBE PRODUCTS INTERNATIONAL