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Tech Center
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High Pressure Side of the Pump There are several accessories that can be added between the pump and the injection valve to help your system function better. The first is a high-pressure prime/purge valve, which is designed to divert your pump's flow away from the column and toward a waste vent. This diversion allows you to run your pump at high speeds, which is sometimes necessary to dislodge air that is stuck in the pump head(s). Air in the pump head can cause erratic flow rates and subsequent baseline noise. The product that is recommended for this application, is our High Pressure Micro-Splitter Valve, the P-460S. This product is capable of handling pressures up to 5,000 psi, and also offers the ability to divert the pump flow as described above. We would also recommend the V-322 valve, if you prefer something that actuates with the simple twist of a syringe. While more expensive than the P-460S, it is simpler to use and can be mounted to a bulkhead panel. Another post-pump product to consider is an Inline Solvent Filter. This product filters the solvent as it passes along the flow path away from your pump through the incorporation of a special frit inside the unit. Inline filters are useful for preventing particles that shed off the pump seals from traveling further along the fluid pathway, where they may cause obstruction at the injection valve or the frit at the head of the analytical column. Our A-315 is recommended for general inline solvent filtration. However, if you need a biocompatible version of the inline solvent filter, we recommend that you try the A-355. This filter is an all-polymer (primarily PEEK™), metal-free filter, which incorporates a 100% PEEK frit (U.S. patent No. 5,651,931, held by Upchurch Scientific). Lastly, for low-pressure LC systems utilizing a reciprocating piston pump, we recommend a back pressure regulator for use as a pump preload. Our U-609—a 500 psi Back Pressure Regulator cartridge encased in a stainless steel holder, is well-suited for this task. When added immediately after your pump, this product forces your pump's check valves to operate more effectively and efficiently, without affecting your sample. It is also helpful to use a back pressure regulator as a pump preload for systems utilizing a gel-packed column. This type of column will often compress and expand slightly under flow fluctuations and overall load. This creates pressure feedback to the pump, which may cause flow irregularities. Having a pump preload in this situation minimizes the effect of the gel column's presence and provides enhanced pump performance. Copyright © IDEX Corporation 2010. IDEX Health & Science is a Unit of IDEX® Corporation. | Privacy Policy |