機器
background
boiler
broken
calcification
calcium
chalky
corrosion
crack
crusty
damage
decay
dirt
domestic
electric
element
equipment
failure
gloves
hand
hard
heat
heater
incrustation
isolated
laundry
lime
limescale
metal
mineral
object
obsolete
old
problem
protect
rubber
rusty
salt
scale
scrap
scum
sediment
soot
steel
surface
technology
washing
waste
water
white