Perform periodic maintenance and repair on doorclosure systems, including but not limited to key card systems and electromagnetic systems.
执行定期保养及维修门关闭系统，包括但不限于钥匙卡系统和电磁系统。
2
Quick-opening closure is a common pressure-bearing component in pressure vessel. Quick-opening closure is often opened with pressure or boosted without closing the door resulting in kinds of accident.