{TAIL ~ The edge} of the partial ball is characterized by having {HEAD ~ a v notch} to obtain desired valve characteristics as well as to provide shearing actions at the sharp edges of the valve as it closes 
{ TAIL ~ The edge } of the partial ball is characterized by having { HEAD ~ a v notch } to obtain desired valve characteristics as well as to provide shearing actions at the sharp edges of the valve as it closes
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH