Heavy wall reaction flask with threaded bottom outlet valve. Part of the one-piece pressure reactor, for use at elevated pressures. With vertical Ace-Thred necks for positive connection of stirrer, funnel, thermowell, condenser, etc. Bottom outlet is a 28/15 O-Ring ball joint (with size -116 FETFE O-Rings, 7855-726) and a threaded valve for retrieving contents of flask.