Gas Chlorination System: Chlorine gas is dosed from bulk cylinders or drums using remote vacuum gas chlorination equipment. The vacuum regulator is mounted directly on the cylinder isolation valve using a lead gasket. Chlorine gas under pressure is fed to the inlet pressure reducing valve, the needle of which is seated on a diaphragm. At the water end of the system, pressure differential is applied across a venturi by a boost flow which causes the venturi to suck. This vacuum is applied to the diaphragm, causing the needle to be pushed into the spring-loaded valve, thereby allowing chlorine gas to flow into the chlorinator. Chlorine Gas under vacuum then flow through a regulating device (needle valve V notch) and through the vacuum tube to the venturi where it is dissociated in water.