This system is based on flanged tubing and UNF ¼” 28 G threads. These threads have their origin in the United States and are mainly used in chromatography/HPLC.” ¼”” stands for the outer diameter of 6,35 mm. “28 G” stands for 28 thread pitches at the length of one inch (25,4 mm).
Following tubing sizes are mainly used in HPLC:
» 1/8” (O.D. approx. 3,2 mm x I.D. approx. 1,6 mm)
» 1/16” (O.D. approx. 1,6 mm x I.D. approx. 0,8 mm)
The screw joint itself consists of a screw (BOLA Tube End Fitting) with washer and flanged tubing. It resists pressures up to 30 bar.
The metal-free washer provides ideal contact pressure of the flanged tubing and prevents small folds during the last phase of tightening the tube end fitting.
The flowing product is only exposed to PTFEGlossaryPTFEPolytetrafluoroethylene – the screw joint has a universal chemical resistance and is absolutely clean.
The PTFEGlossaryPTFEPolytetrafluoroethylene tubing to be flanged must be made of a special type of PTFEGlossaryPTFEPolytetrafluoroethylene . Our tubing fulfils this requirement (see page 198). Besides PTFEGlossaryPTFEPolytetrafluoroethylene tubing, there can also be used FEPGlossaryFEPTetraflouroethylene-Perflouropropylene and PFAGlossaryPFA Perfluoroalkoxy tubing (both gastight and transparent).
The different colours of the tube end fittings can be used for distinction.
They consist of a screw cap made of glass-fibre reinforced PPGlossaryPP Polypropylene with GL 45 thread and a movable body with connection ports. All necessary screw joints and gaskets for connecting hard-walled tubing (e.g. PTFEGlossaryPTFEPolytetrafluoroethylene , FEPGlossaryFEPTetraflouroethylene-Perflouropropylene or PFAGlossaryPFA Perfluoroalkoxy ) up to a maximum diameter of 6 mm are included in delivery and make the HPLC distributors usable immediately.
Tubing up to a diameter of 4 mm can be passed and fixed absolutely tightly at the requested immersion depth.
The distributors with stopcocks allow closing unused ports; the FEPGlossaryFEPTetraflouroethylene-Perflouropropylene stopcock plug provides a universal chemical resistance.
Because of the stopcocks, it is not possible to pass the tubing. A connection to the bottom of the bottle can still be made by pushing tubing with O.D. of 5 mm or
I.D. of 6 mm in or on the port on the lower side of the distributor.
A possible unevenness of the bottle neck is adjusted by an o-ring behind an elastic sealing lip, and the bottle is closed tightly. The product is only exposed to the body of the distributor.
The special feature: the body of the distributor can be turned independently from the screw cap. This means, that the completely assembled distributor can be removed and fixed on another bottle without the risk of disarranging the tubing.