Vacuum operate membrane valve

The SYMPHONY/Multiplex (Figure 8), introduced in 1993, is a batch (Boc/Fmoc peptide synthesizer with 12 independent reaction vessels (49). The key component is the patented matrix valve system that enables different solutions to be transferred to each of the 12 reactors simultaneously. This feature allows the assembly of 12 different peptides under optimal conditions for each sequence with regard to scales and customized coupling reactions. Solution flow is controlled via chemically resistant membrane valves arranged to provide a matrix system with common solution ports but separate delivery lines for each reaction vessel. A combination of gas pressure and an external vacuum pump operates the valve system. Solution transfer is achieved by nitrogen pressure. 

The membrane characterization data reported in this section have been obtained by means of the apparatus shown in fig. 11. It is made of stainless steel and can operate fi om high vacuum up to 70 bars. In addition, it is characterized by the unique capability of performing a broad range of porous membrane characterization and evaluation measurements, namely equilibrium isotherms, absolute (integral and differential) and relative gas and condensed vapor permeabilities and selectivities. Each of the two membranes, accommodated by the facility, is connected to the high and low pressure sections through four valves MiH, MiL, MiHF, MiLF (i=l, 2, 3). 

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