{TAIL ~ The safety relief valve control valve} acts to modulate the operation of {HEAD ~ the safety relief valve} when there is flow from an outflow port 
{ TAIL ~ The safety relief valve control valve } acts to modulate the operation of { HEAD ~ the safety relief valve } when there is flow from an outflow port
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH