Cylindrical, jacketed, peptide synthesis reaction vessel having a coarse porosity fritted resin support. The vessel is constructed with a flange having a groove formed in the sealing surface of the flange. Flange is also ground to permit a greased seal with any of the corresponding lids. Lower outlet is a CG-511 bottom drain valve. Cooling jacket is equipped with two removable hose connections to reduce the risk of injury while attaching or detaching flexible tubing. Supplied complete with two polypropylene hose connections and two GL-14 screw caps. For the clamp see CG-141 and for the o-ring see CG-147. Lid Not Included.