aqueduct
blurred
central
central heating
communication
conducting
conduit
duct
energy
equipment
heating
heating main
hot
hydropower
industry
infrastructure
insulation
large
line
main
metal
municipal
old
outdoor
outside
pipe
pipeline
plumbing
selective focus
snow
steam
steel
stream
structure
supply
system
technology
thermal
transfer
transit
transmission
transporting
trunk
tubing
urban
water
water supply
winter