A water system 15 selected from {HEAD ~ the group} consisting of geothermal water, {TAIL ~ water} in central heating systems, and water for hydrostatic tests 
A water system 15 selected from { HEAD ~ the group } consisting of geothermal water , { TAIL ~ water } in central heating systems , and water for hydrostatic tests
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH