英文關鍵字
background
blue
bolt
connect
connection
construction
contractor
energy
engineering
equipment
factory
flange
flanged
flow
fuel
gas
gasification
heavy
industrial
industry
infrastructure
iron
joint
line
manufacturing
mechanic
metal
oil
part
pipe
pipeline
piping
plant
plumbing
pressure
production
round
screw
screwed
steel
structure
supply
system
technology
trading
transportation
tube
valve
water
work