a valve body defining a main valve cavity and {TAIL ~ a smaller diameter metering valve cavity}, with {HEAD ~ a narrow interconnecting passage} between them, 
a valve body defining a main valve cavity and { TAIL ~ a smaller diameter metering valve cavity } , with { HEAD ~ a narrow interconnecting passage } between them ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH