Valco high pressure on/off or prime/purge valves feature quality engineering, precision machining, and extremely low internal volume (< 2 µl), making them the ideal choice in the most demanding liquid or supercritical fluid chromatography or extraction systems (not suitable for use with gases). The valve needle is made from a special high strength alloy which is resistant even to the buffer salts which might accidentally precipitate inside the valve. Seals are fluorocarbon, with valve bodies machined from HPLC grade stainless Steel, ensuring long lifetime in even the most demanding situations.The on/off function is self-explanatory; in prime/purge models, mobile phase flows around the needle when the valve is closed, relieving the back pressure from the column. When the valve opens, mobile phase vents to waste to prime the pump.Standard models provide leak-tight operation up to 10,000 psi liquid (690 bar) at 100°C, with high temperature versions rated up to 6,000 psi liquid/300°C. A 1/16" fitting model with a larger bore and a 1/8" fitting model (rated at 2000 psi liquid) are available for high flow applications.
