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Tech Center
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Pump Pump Check Valves, Pistons and Piston Seals are often replaced on a routine basis (annually or bi-annually). However, due to the pump specificity of these products, we recommend that you visit pump accessories in our browse section. After the search is completed, review the products of interest, based on the manufacturer(s) of your pump(s). Our product line currently includes check valves, pistons and/or piston seals from the following pump manufacturers: ABI, Beckman, Bio-Rad, Dionex, Eldex, Gilson, Gynkotek, Hewlett-Packard, Hitachi, ICI, ISCO, Knauer, Kratos, Perkin-Elmer, Pharmacia, Shimadzu, SSI, TSP/LDC, TSP/Spectra-Physics, Varian and Waters. There are also standard products, such as tubing and fittings, which are often used throughout HPLC systems. For the solvent inlet tubing, we typically recommend Teflon® tubing, our part number 1523 (1/8" OD x 1/16" ID). Additionally, connecting this type of tubing to most pump inlet check valves requires the use of standard 1/4-28 Flangeless Fittings and Ferrules. For the fittings, we recommend the P-300 ferrule, a Tefzel®-based product, to be used with one of the following nuts: the P-301, an excellent, low-cost nut manufactured from Delrin®; or the P-330, a PEEK™ polymer-based nut which offers excellent solvent resistance and, unlike the Delrin nut, can be used with most acidic and basic solutions. For the high-pressure side of the pump, i.e. after the pump head(s), 1/16" OD Stainless Steel or PEEK Polymer Tubing is often used, typically with a .010" inner diameter. Therefore, the products we recommend are our U-112 (10 cm long) or the U-113 (20 cm long) for stainless steel needs, and the 1531B PEEK tubing (5 feet long) for biocompatible applications. PEEK polymer tubing is recommended in general as an excellent replacement for stainless steel tubing, due to its excellent chemical resistance, its ability to withstand high pressures, and because it is much easier to cut. If you choose to use PEEK tubing, we certainly recommend that you take advantage of the A-327 Polymer Tubing Cutter to produce a flat, concentric cut on your tubing. In addition to the required tubing, you will need special high-pressure fittings. Most pumps have the flow path tubing leaving the pump connected to the outlet check valve, and most outlet check valves incorporate a 10-32 threaded, coned port. To make a connection to this style of port, the first decision to make is whether or not you wish to use stainless steel or polymer fittings (like Fingertights). Stainless Steel Fittings, such as our U-400 nut and our U-401 ferrule, will certainly hold your tubing in place under higher pressures than polymer fittings are able to do. However, they permanently attach to your tubing, which makes them difficult, problematic, and expensive to change. Due to the various drawbacks of using stainless steel, many analysts opt to use polymer fittings. The most popular choice of Fingertight Fittings includes the F-120, a one-piece PEEK™ polymer fitting which incorporates both the nut and ferrule portions of the connection into one product. We also recommend our F-195 SealTight fittings system, which is a two-piece setup. Both styles of polymer fittings are able to hold tubing to several thousand psi and work exceptionally well on both stainless steel and PEEK tubing. For interchangeability, it is best to use a Fingertight style fitting wherever possible. Not only is this easy to use, it also can be used in multiple ports, as it does not attach permanently to the tubing wall. Copyright © IDEX Corporation 2010. IDEX Health & Science is a Unit of IDEX® Corporation. | Privacy Policy |