Should the first filter member become clogged, {HEAD ~ the oil pressure} will rise above {TAIL ~ a safe value} 
rise above
Should the first filter member become clogged , { HEAD ~ the oil pressure } will rise above { TAIL ~ a safe value }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL