英文關鍵字
steel
stainless
pipe
metal
valve
pipeline
tube
water
equipment
industry
industrial
iron
technology
factory
construction
piping
silver
engineering
blue
line
chrome
barrel
cylinder
abstract
background
gas
plant
chemical
power
fuel
big
modern
sewage
electricity
nuclear
tool
nobody
pairs
transportation
concrete
metallic
clean
accessory
shiny
washing
white
manufacturing
tank
trap
cold
plastic
bag
warehouse