{TAIL ~ A piston pump} 17 wherein said wear pad is made of {HEAD ~ a polyethylene} 
{ TAIL ~ A piston pump } 17 wherein said wear pad is made of { HEAD ~ a polyethylene }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD