A continuous-purge pulsed valve has been designed to introduce supersonic jet samples into a vacuum chamber. The new valve design separates the heated sampling and transfer lines from the solenoid coils with a long metal valve stem, which is kept cool with annular cooling fins. The valve is heated using electrical heating elements wrapped around the valve stem. A precision-machined stainless steel plunger maintains a metal-to-metal seal at the valve orifice, which is broken when the induced magnetic field from the solenoid pulls the plunger upward. Stable gas pulse widths were obtained down to 200 &mgr;s, which compares favorably with the 165 &mgr;s value for the commercial unit which uses a small Teflon poppet instead of the metal plunger. ©1997 American Institute of Physics.