Upchurch Scientific® Inline Check Valves provide excellent backflow protection for sensitive equipment along with outstanding chemical resistance only available from PEEK™ polymer and perfluoroelastomer. Metal-free composition makes these check valves perfect for use with corrosive fluids or biological samples.
These check valves function well in both low and high pressure applications. Low internal volume also allows them to be used in areas where flow path volume is important; however, higher flow rates can pass through with minimal pressure drop. All six Nonmetallic Inline Check Valves have a 0.020" thru-hole [We also offer 0.040" and 0.060" thru-hole versions of CV-3320 and CV-3321 (CV-3322, CV-3324, CV-3323 and CV-3325, respectively)]. All six also feature a springless design with 1 psi (0.07 bar) cracking pressure.
Direct-connect the CV-3320 or CV-3321 to any 1/4-28 flat-bottom port for trouble-free back flow protection. If you are using a pump after your analytical column, consider placing a CV-3330 Check Valve after the column to prevent fluid from the post-column pump from flowing backwards through the column. This product also serves as an excellent nonmetallic alternative to our CV-3010 in sparging applications where the mobile phase may be corrosive to the stainless steel or ethylene propylene components inside the CV-3010 assembly.
The configuration of the CV-3335 Inlet and CV-3336 Outlet Check Valves allows tubing larger than 1/16" OD (up to 1/8") to be connected into a 10-32 coned internal port. Use both of these check valves when attaching a larger-volume sample loop to an analytical-scale injection valve. This setup limits the flow of the sample into the loop to one direction, minimizing back flow and sample carry-over. The CV-3340 is useful in virtually any high pressure fluid pathway using 1/16" or smaller OD tubing, where limiting the direction of flow is desirable.
The Nonmetallic Inline Check Valves with 1/4-28 flat bottom internal ports can accommodate 1/32", 1/16", 1/8" and metric (1.0 - 3.0 mm) OD tubing, depending on the fittings used. Select from the broad line of Upchurch Scientific Flangeless, Super Flangeless™ and VacuTight™ fittings.
The Nonmetallic Inline Check Valves with 10-32 coned internal ports are compatible with standard 10-32 threaded polymer Fingertight and SealTight™ Fittings - metal fittings are not recommended as they may damage the ports. These ports can also accommodate NanoTight™ Fittings and Tubing Sleeves to connect capillary tubing.
Tighten check valves with external threads into the appropriate receiving port using a 9/16" wrench (1/4 turn past finger tight) before connecting tubing and fittings into the internally threaded end.