In the other survivor, the valve closed up again and had to be reopened several times after the child was born.

He felt that valves opened for him and closed behind him.

Thus, the spring is irrelevant to holding the valve closed.

Keep the valve closed during the day so that you can talk and breathe normally.

Looking up, she could see that the lower valve had closed.

I enter the room and the valve closes behind me.

With the sunrise the next morning, the valve would close.

As the saucers moved about the field, the valves would open and close in response to their proximity.

Once the pressure reaches the set point, the valve closes.

Lights above the panel showed that the indicated valve was closing.