The Solinst Double Valve Pump (DVP) is a pneumatic drive pump that allows consistent, high quality samples. It has been field proven in hundreds of applications. It offers excellent performance and reliability; no bladder replacement and higher pumping rates than with the Bladder Pump; a selection of sizes and materials; variable flow rates; and is field serviceable. The DVP is suitable for low flow or regular flow sampling, and can operate to depths of 2000' (600 m) and more.