So if the valve fails, the well will not be sealed.

A valve had failed to send water for the boiler to heat into steam.

Seven days later, the same valve failed, during the night, again when no one was at the school.

Secondly, the valve failed when the pressure differential became too great.

But when the fountain was turned on again, a key valve failed.

However, bicuspid valves are more likely to deteriorate and later fail.

But in December 1985, the valve for this hazardous space dump had failed its qualification test.

A valve used to release helium into the tank failed to open.

For instance, blood circulation in the cardiovascular system is maintained to some extent even when the heart's valves fail.

Dr. Vaughn said the valves fail without warning and seemingly at random.