| 摘要 |
<p>One or more valves associated with a controlled machine process may be isolated from one or more remote isolation stations. For isolation, a manual switch is activated that are coupled to a safety relay. This relay is, in turn, coupled to a coil that removes power used to control the valve to be isolated. An operator-perceptible indication may be provided by monitoring a parameter representative of the valve state, such as pressure downstream of the valve. Such indication may be provided at each remote isolation station. The arrangement allows for lock-out of valves by remote operation.</p> |
