Siemens Water Technologies offers a wide range of filter cartridges and housings to meet various application and removal needs. The WN Series are composed of a double layer of integrity testable, highly asymmetric polysulfone membrane. Long on-stream life, high flow rates and low pressure drops result from this membrane's asymmetry. The high-purity construction materials are factory flushed with DI water for quick on stream rinse-up with a minimum of throughput.