{TAIL ~ The throttle valve} has at least two variable orifices and a compensation chamber between {HEAD ~ the variable orifices} 
{ TAIL ~ The throttle valve } has at least two variable orifices and a compensation chamber between { HEAD ~ the variable orifices }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD