Valve, Chem-Vac, Chem-Cap, Hi-Vac, 1-Arm, 0-8mm Bore. CHEM-VAC CHEM-CAP valve has a single sidearm sealed at a 90 angle to the barrel. This inexpensive configuration allows for the lower portion of the barrel to be sealed directly to the apparatus being constructed, making for more compact, stronger assemblies. See CG-961 for replacement CHEM-CAP plug and CG-902 for glass portion only.