Procedures and regulations regarding long-term disconnection of interlocks
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I’ve run into a problem recently and would like to ask everyone for advice. It is about the interlocking mechanism when several devices share one main control valve or pump; since some of these devices are in standby mode and may not be used for a long time, it is necessary to disable such interlocking. In accordance with the requirements for interlocked shutdown operations, the prolonged interlocked shutdown for Grade A cannot exceed 15 days, while that for Grades B and C cannot exceed one month. However, the equipment might not be used for months, and issuing tickets repeatedly is an illegal practice. What should be done in this situation?
Is it an indication of unreasonable process design to have multiple devices share one isolation valve, or should there be one isolation valve for each device?
The pump of the storage tank? A/B pumps, serving as backups for each other. There’s no need to cut it.
The impact of backup equipment on the operating equipment constitutes a chain reaction, which is due to an unreasonable design of the chain mechanism. It is recommended to modify the chain plan.
The process flow diagram and interlock control diagram have been printed out for everyone to discuss.
The key issue with your question is that “processing tickets repeatedly is also an illegal practice.” ”Regarding the \"illegal operation\" issue, it is necessary to determine which law governs this situation, check whether your device is in conflict with it, and resolve such issues following the established procedures. Just report the issue upward along with reasonable suggestions. If discussing reasonable settings, it’s best to send a simple diagram to facilitate the discussion. For reference.
This is inherently a case of poor design; it needs to be redesigned
Design a redesign; it’s likely that the process is not reasonable
Regarding your issue with interlock removal, to achieve long-term removal of the interlock, you need to submit a change request, explaining the situation in detail along with a thorough risk analysis