Application

The PSQ membrane filters consist of a stainless steel, PTFE or PVC housing with a porous membrane filter, which is supported by a sintered porous disk located on the "outlet" side of the housing. Gas enters through the "inlet" port on the upstream side of the membrane and exits from the "outlet" port on the downstream side. Any liquid in the gas sample will flow to the drain port, completely protecting sensitive instrumentation such as process analyzers from moisture. This port can also be used as a bypass function for the main flow which helps membrane to operate correctly. If membrane filters constructed with stainless steel material, the housings are free from welds and comply with NACE MR-01-75. Filter housings are mostly fitted with Viton O-ring style seals as standard.

The Membrane Function

Conversely, even the smallest liquid molecules remain trapped and are unable to flow through the membrane's small passages under normal operating conditions. This is due to the high surface tension, which causes liquid molecules to bind tightly together, to form a group of molecules, which is too large to fit through the pores of the membrane. The membrane is extremely inert and is recommended for most process applications. It is also recommended for use in systems designed for ppb, ppm and "percent level" component concentrations, as a result of its very low absorption characteristics. The membrane is strong and durable, but also very soft and pliable.

The Membrane Grade and Dimension

Microscopic pores contained within the membrane is manufactured from a pure PTFE supplied from the best manufacturers, permit molecules of gas or vapor to flow through easily, allowing the composition of the sample gas to remain unchanged. Type of membrane shall be suitable for each application. In this case, suitable PTFE type, pore size and thickness as well as application should be selected from table below.