There are two different concepts for safe clearance in tank farm:fire safe clearance, and protective safe clearance.

油库安全距离有两个不同的概念，一个是防火安全距离；另一个是防护安全距离。

youdao

The protective safe clearance for a hidden tank shall be determined in accordance with the level of allowable destruction, location of explosion, and the safe clearance between two hidden tanks.

对于带有掩体的油罐，其防护安全距离的确定应根据允许破坏等级、爆炸位置以及有掩体的两油罐间防护安全距离的计算来确定。

youdao

The electric clearance check of tower head is an important measure to ensure the safe operation of overhead transmission line.

塔头电气间隙校核是保证架空输电线路安全运行的重要措施。

youdao

Therefore, full safe clearance is never done during the day (except in emergency repair situations), and nighttime is the only time all the major maintenance work can be completed.

FORBES: Why Does BART Need To Do Nightly Maintenance?

The report includes that the safe was accessible to more than a half dozen Gonzales staff members who did not have clearance to see such material.

NPR: Report: Ex-AG Gonzales Mishandled Classified Info