loaded valve

loaded valve

A spring loaded valve for use with laboratory glass tubing  in which a valve member  is spring loaded against a seat. A cap is screwed onto the tubing. An actuating rod  is attached to the valve member  and extends through the valve cap. A lever  is pivotally mounted to the extending portion of the actuating rod and operated in such a manner as to provide a clamming action to permit the opening and closing of the valve  against spring bias. The spring  is located between the inside of the cap and a sealing member abutting a shoulder within the valve member. The cap  is screwed onto the tubing to provide a predetermined closing pressure of the valve on the seat to prevent breakage of the glass tubing. In a second embodiment the lever mechanism is omitted and the spring loaded valve member includes a support member located in the hollow portion of the valve member  and the spring is located between the inside of the cap and the flange  of the valve member. A retaining ring is screwed into the cap. The valve is actuated by rotating the cap and a reduced thread profile within the cap prevents over tightening the valve member on its seat.