Designed by Dr. Raymond Firestone, this rapid and efficient purge valve is designed to allow 100% replacement of air in reaction vessels with any desired gas. No mercury is used, no reducing valve is needed on the gas source, and no high-vacuum source is required. The valve also eliminates the need to watch manometers, hand-control gas flow, or install warning systems. Expensive gases are conserved as the flow can be cut to nearly zero when purging is complete. This economic valve makes it possible to run all reactions under nitrogen.
Designed by Dr
To operate, simply connect the reaction vessel, house vacuum, and purge gas to the valve via 10 mm O.D. connections or O-ring joint. On vacuum cycle, air is removed from the reaction vessel while the stop valve is closing. When filling is complete, the stop valve reopens to prevent pressure buildup. Thus, a simple half turn of the stopcock alternates the reaction system from vacuum to gas flow as fast as desired. In small systems, a complete cycle takes as little as one to two seconds. With only ½ atmosphere house vacuum, ten cycles removes all but 510 atmospheres of air. About 70 cycles gets you down to the last molecule of oxygen.
After purging, the system is kept under slight positive pressure indefinitely with a slow bubbling of the gas to prevent diffusion of air past the joints. If the reaction evolves a gas, no pressure builds up, and it may even be collected and measured in a controlled atmosphere. Proper liquid selection for the seal allows purging with any gas that does not react with glass. Liquid not supplied. Manufactured from borosilicate glass.
Raymond Firestone, this rapid and efficient purge valve is designed to allow 100% replacement of air in reaction vessels with any desired gas. No mercury is used, no reducing valve is needed on the gas source, and no high-vacuum source is required. The valve also eliminates the need to watch manometers, hand-control gas flow, or install warning systems. Expensive gases are conserved as the flow can be cut to nearly zero when purging is complete. This economic valve makes it possible to run all reactions under nitrogen.
