For vacuum applications up to 5 x 10 Torr. Designed with a precision external thread for fine control. This valve can be used as a bleed up to 1/2 a turn. Full open position is at 1 1/2 turns. The shaft is non-rotating and the primary seal is made with a Viton o-ring on a tapered seat. PTFE shaft can be used continuously at system temperatures of 230°C, or intermittently at 275°C. Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements.