Valve Shutoff System Improves Safety of Chlorine Gas Applications
Halogen Valve Systems' Terminator® automatic valve shut off system has been developed
Halogen Valve Systems' Terminator® automatic valve shut off system has been developed to meet the more stringent safety requirements imposed by the Process Safety Management (PSM) and Risk Management Plan (RMP) requirements.
The system is a battery powered fail-safe device designed to provide safety and security where toxic gas cylinders are in use. In addition, the Terminator meets the requirements of the Uniform and International Fire Codes for storage and use of toxic gases such as chlorine, sulfur dioxide, and hydrogen sulfide. It is an accepted technology to replace scrubbers for gas leak containment.
The automatic valve shutoff system was designed to respond to the requests of utilities that need to improve plant safety and security for the demanding needs of current regulations. The system will close up to two cylinder valves through a controller designed to meet the needs of smaller installations.
An automatic valve operator (AVO) is mounted on each cylinder and will close the cylinder's valve on signal from the controller. The controller can receive any number of closure signals from sensors such as a gas leak detector, seismic sensor, fire alarm, and emergency panic button.
The secret to the success of the system and its popularity with consultants and safety officials is that the Terminator will only automatically "close" the valve. That means that the operator must open the valve manually. This requires an on-site assessment of the situation that caused the AVOs to close the container valve. Once an operator has reviewed the situation and taken any corrective action, the valve can then be opened manually. Manual opening of a cylinder valves after an emergency closure is a requirement of the Chlorine Institute's design standards for automatic valve shutoff systems.
The battery operated system will provide sufficient power to close any valve as long as the sensors are operational. The controller and actuator meet NEMA 4X electrical standards and are well suited for the corrosive conditions that can be experienced at water and wastewater treatment facilities.
Experience with equipment installation and personnel training on the use and operation of AVOs has shown that only one hour of training is required. As a result of the simple instructions, plant maintenance personnel can complete installation of the system in less than an hour. The only requirement for tools during installation will be to wall mount the controller and to wire the system. Electrical power from a 115 or 230 V, 50/60 cycle source is necessary for the battery charger located in the controller.
The system's design also provides for testing at each cylinder change. Testing procedures require no special tools and are part of a regular work practice requirement for operation personnel.
Available since 2001, the Terminator has been installed in many locations in the United States as well as internationally and has been adapted to a variety of different cylinder installations. Since its introduction, several chlorine gas excursions could have become major incidents but were relegated to minor incidents due to the fast action of the shutoff system.