Double seated fluid stop valve - has diaphragm shutting leakage chamber off from atmosphere before opening

摘要

The fluid stop valve has two valve plates rigidly fixed to a spindle, forming two seals with a leakage chamber between , connected to atmosphere in the shut position. Before the valve is opened by lifting the two plates (1,2) off their seats, the connection to atmosphere is shut off by a diaphragm (5). Alternatively, this can be done by a third movable plate between the other two. The design avoids any risk of product leakage to atmosphere during operation of the valve.