abandoned
bolt
close up
corrosion
detail
device
dirt
dirty
drainage
energy
equipment
faucet
fuel
gas
grunge
history
hydrant
industrial
industrial equipment
industrial revolution
industry
iron
line
mechanism
metal
obsolete
old
pipe
pipeline
plumbing
power
pressure
retro
rust
rusty
steel
supply
system
technology
tube
valve
wall
waste
wheel