Thereby, {HEAD ~ the heater section} is furnished with at least one distance control means arranged for being in contact with the shell surface during the heating and for automatically regulating the second distance by means of {TAIL ~ a self regulating mechanism} 
Thereby , { HEAD ~ the heater section } is furnished with at least one distance control means arranged for being in contact with the shell surface during the heating and for automatically regulating the second distance by means of { TAIL ~ a self regulating mechanism }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL