Butterfly designs for these devices, which are based on a disc that rotates around a shaft, have a low pressure drop in the open position when the disc is parallel to the flow direction. For 10 points each:
[10e] Name these devices that regulate the flow of a fluid through a pipe.
ANSWER: valves [accept any kind of valve, such as butterfly valves or check valves]
[10m] This hazardous condition can be prevented using double check valve assemblies. This condition occurs when a fluid moves in the wrong direction through a cross-connection into the distributing pipes of a potable water supply.
ANSWER: backflow [accept backsiphonage or backpressure]
[10h] This common cause of failure for check valves occurs when the valve is oversized for the application. This phenomenon, which is named for the sound it produces, is the rapid opening and closing of a valve, leading to vibrations that increase wear and damage the valve seat.
ANSWER: chattering
<ES, Other Science (Engineering)>