Valve, Chem-Vac™, Chem-Cap, Hi-Vac, Metering, 90, 0-4mm Bore. CHEM-VAC™ CHEM-CAP metering valve has an extended tip on the plug to allow semi-needle valve control of gases and liquids. Valve has two sidearms sealed to the barrel at a 90 angle to one another. See CG-971 for replacement CHEM-CAP metering plug and CG-903 for glass portion only.