Users of chlorine now regulated by the newly created 2003 International Fire Code and the 2003 Edition of the Uniform Fire Code are no longer required to have a scrubber when storing or using 150-lb cylinders or one-ton containers of liquefied chlorine gas.
For indoor and outdoor storage, the need for a scrubber is eliminated when:
1. Chlorine cylinder valve outlets are equipped with gas-tight outlet plugs or caps.
2. Where approved containment vessels or containment systems capable of fully containing or terminating a release are available or that are capable of being transported to the leaking cylinder, container or tank.
For indoor and outdoor use, the need for a scrubber is eliminated when:
1. An approved automatic-closing fail-safe valve is located immediately adjacent to the cylinder valves. The fail-safe must close when gas is detected at the permissible exposure limit (PEL) by a gas detection system monitoring the exhaust system at the point of discharge from a gas cabinet, exhausted enclosure, ventilated enclosure or gas room.
2. Where approved containment vessels or containment systems capable of fully containing or terminating a release are available or that are capable of being transported to the leaking cylinder, container or tank.
Plant operators have found that fail-safe valves and containment vessels require little or no maintenance, repair or replacement.
A fail-safe valve is typically described as a 1/4 turn ball valve that is spring loaded, always fails in a closed position and does not rely on any electrical power or backup emergency power to close the valve.
Unmanned sites located in densely populated areas are especially in need of a system to process chlorine from cylinders or ton containers that will release little or no chlorine gas to the surrounding community.