Further through the special construction clogging or {HEAD ~ plugging} of the ports is minimized by the distribution through the radial ports and {TAIL ~ a circumferential recessed protective groove} adjacent the plug end 
Further through the special construction clogging or { HEAD ~ plugging } of the ports is minimized by the distribution through the radial ports and { TAIL ~ a circumferential recessed protective groove } adjacent the plug end
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH