Manhole Cover with Trapped-Key Interlocking System
Locked – and safe!
Containers, silos and chambers where entering is connected to a higher safety risk often do not have a proper safety system that would prevent an opening of the maintenance accesses during dangerous operational conditions.
The easily retrofittable Bilfinger GreyLogix foodtec trapped-key interlocking system ensures that maintenance accesses are locked until there is no danger for people or plants anymore. In the same manner, it prevents dangerous operating conditions when the accesses are open, e.g.restarting the plant or activating the explosion suppression.
Therefore, a locking mechanism is installed at each maintenance access, e.g. manholes, sliding or swinging doors or hatches, which can be opened only with a key specifically designed for this mechanism. This key can only be removed from the lock after locking the maintenance access.
When the plant is in operation, the keys are in a key board which has an electronically monitored slot for each key. Upon taking the key the plant is locked against unsafe operating conditions, meaning that e.g. restarting the plant is only possible when all keys are put back in the key board.
The Bilfinger GreyLogix foodtec trapped-key interlocking system does not require any additional cabling to the maintenance accesses, so it is suitable for retrofitting in existing plants.
- doubled safety by mechanic locking of the accesses and electronic monitoring of the key slots (electronic locking)
- individual key bits for each locking system
- inclusion to emergency stop chain (when trying to take out a key during operation)
- easily retrofittable, as no cabling to the accesses is needed
- protective measures can be installed easily by the operating authority, within the meaning of BetrSichV
- for areas where people could get locked in: additional personal keys