The SSV series stream selector system delivers a representative sample from multiple sample streams to a single analyzer. These modular assemblies are ANSI/ISA 76.00.02 compatible. They can accommodate multiple process streams in a limited amount of space. Each stream is controlled by a double-block-and-bleed (DBB) module to eliminate cross contamination and maintain sample integrity. Based upon a modular technology concept, these valves house all functions within a single, compact module to reduce total space needed to perform sample stream selection and overall installation time. As system requirements change, modules can be added or removed. The SSV series stream selector system features an integrated flow loop to streamline sampling and purging and provide consistent outlet flow. Regardless of which stream is selected, the flow rates of all streams remain consistent.