Jacketed flask with bottom outlet for pressure reactor system designed to perform low to moderate positive pressure reactions, synthesis and catalysis. Reactor flask capacity is 3000 ml and uses Ace-Threds to achieve a leak-tight system and 150 mm flange. Two-piece (flanged flask and head) design allows the use of large agitators and facilitates product removal and clean-out. Rated 36 PSIG at 100°C.