black and white
conduit
container
crude oil
cylinder
deliver
delivery
diminishing perspective
duct
economic
energy
environment
factory
flammable
fuel
gas
gasoline
industrial
industry
line
manufacture
manufacturing
metal
monochrome
oil
oil tank
petrol
petroleum
pipe
pipe line
pipeline
piping
plant
power
production
resource
steel
storage
structure
supply
system
transmission
tube
valve
vanishing point
warehouse