What is the minimum and maximum time a door can close?

What is the minimum and maximum time a door can close?

• A. 2 to 6 seconds
• B. 8 to 12 seconds
• C. 5 to 10 seconds
• D. 10 to 15 seconds

Answer: (C)

Doors, especially watertight or fire doors, are intended to close in a controlled time to balance a solid seal with safe operation. If a door moves too fast, it can slam, miss the seal, or cause injury, while closing too slowly leaves a compartment exposed longer to water, smoke, or heat. The operating standard is a window that allows enough time for the door to travel fully and engage the seal, but isn’t so slow that safety is compromised. Five to ten seconds achieves that balance, providing reliable sealing and timely isolation. The other ranges either try to close too quickly or take too long, which can undermine protection or safety.

Doors, especially watertight or fire doors, are intended to close in a controlled time to balance a solid seal with safe operation. If a door moves too fast, it can slam, miss the seal, or cause injury, while closing too slowly leaves a compartment exposed longer to water, smoke, or heat. The operating standard is a window that allows enough time for the door to travel fully and engage the seal, but isn’t so slow that safety is compromised. Five to ten seconds achieves that balance, providing reliable sealing and timely isolation. The other ranges either try to close too quickly or take too long, which can undermine protection or safety.