The corrugation 22, concave arc portion 32 and {TAIL ~ horizontal flat portion} 24 are located sequentially along {HEAD ~ the axis} of pipe 20 
The corrugation 22 , concave arc portion 32 and { TAIL ~ horizontal flat portion } 24 are located sequentially along { HEAD ~ the axis } of pipe 20
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH