c. Connection from Cylinder to Chlorinator.
(1) Temperature considerations. If the temperature of the chlorine cylinder
is higher than the chlorine feed lines, chlorine can condense in the lines. Condensation
can be prevented by reducing the pressure with a pressure-reducing valve. In no case
should supply lines be run along cold walls or exterior windows. If heat must be
applied, it should be applied by heating the entire space. Localized heat should not be
applied directly to the tank or lines.
(2) Pipe fittings and connections. New gaskets should be used on all
connections. Piping systems should be well supported and adequately sloped to allow
drainage; low spots should be avoided. A lubricating pipe dope suitable for chlorine
should be used. Linseed oil and graphite, linseed oil and white lead, or litharge and
glycerine (for permanent joints) may be used.
(3) Cylinder valve. The cylinder valve is opened by turning the valve stem
one full turn in a counterclockwise direction. Special 3/8-inch square box wrenches
should be used for turning the valve stem. A wrench longer than 6 inches should not be
used. Leaks at this valve can be stopped by tightening the packing nut at the valve
d. Detecting Leaks.
(1) A small piece of cloth soaked with ammonia and wrapped around the
end of a short stick can be used to detect leaks. If chlorine gas is leaking, a white cloud
of ammonium chloride will form. Commercial 26 Baume aqua ammonia should be
used; household ammonia is not strong enough.
Avoid contact of ammonia with copper or brass.
(3) Never use water on a chlorine leak. The corrosive action of chlorine and
water always will make the leak worse.
e. Ventilation. High and low ventilation should be supplied for chlorine rooms.
The suction point of exhaust fans should be located at or near floor level. A 2-minute air
change should be provided. Switches for all ventilating fans should be provided outside
of chlorine rooms even when an inside switch is installed.
f. Determining When a Cylinder is Almost Empty.
(1) Weight. One hundred pound cylinders and 150-pound cylinders will
have lost their rated net content.
(2) Gas pressure. The gas pressure gauge will show a marked drop when a
cylinder is empty.