機器
anode
boiler
boiler deposits
broken
calcium
cooper
corrosion
corrosive
curl
cutout
damage
deposition
deposits
dirt
dirty
electric
element
equipment
failure
grunge
heat
heater
heating
hot
iron
isolated
magnesium
metal
mineral
object
obsolete
old
part
repair
rust
rusty
scale
scrap
scum
sediment
service
stone
tubular
unhygienic
utensil
water
white