The check valves, or unidirectional valves, are widely used in all hydraulic applications, from the mobile to the industrial sector. The VUR-BSPP are unidirectional valves for in-line installation. The shutter, poppet or ball, is housed inside a body with female threads, available in sizes BSPP 1/8 to BSPP 2. The oil flow is free from port 2 to port 1 while it is interrupted by port 1 to port 2. For VUR-BSPP unidirectional valves the standard opening pressure of the shutter is fixed at 1 bar; different opening pressures are available on request. According with the size, the VUR-BSPP check valves are suitable for systems with flow rates up to 430 lpm (113,5 gpm) and maximum working pressures up to 400 bar (5800 PSI). The external body is made of high-strength steel and protected externally from corrosion by galvanizing treatment. The zinc/nickel surface treatment is available on request and is recommended for those applications exposed to corrosive agents, such as particularly aggressive environmental factors.