機器
abstract
ancient
background
boiler
brown
building
closeup
construction
detail
electric
equipment
factory
faucet
fuel
gas
generation
ground
hand
heat
heavy
industrial
industry
iron
ladder
line
metal
metallic
object
oil
old
pipe
plant
power
regulator
repair
safe
station
steel
stress
supply
technology
tool
transfer
transportation
valve
vintage
water
wellhead
work