Home / Markets / WEAVALVES / Products / Valves / Valves / Check Check Check valves are back flow prevention valves. There are in-line and flap models. They are economical and used for both commercial and industrial application. A few models are designed with a smooth flow profile to minimize head loss and accumulation of debris. Series BICV Economical, Spring-Loaded for Fast SeatingBrass Inline Check Valve is ideal for use with a broad array of service mediums including compatible oils, gases, fuels, and hydrocarbons. Designed with a smooth flow profile to minimize head loss and accumulation of debris.