A piston valve and a piston are fastened into {HEAD ~ an inner compression chamber} inside {TAIL ~ the compression cylinder} 
inside
A piston valve and a piston are fastened into { HEAD ~ an inner compression chamber } inside { TAIL ~ the compression cylinder }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL