black
chemical
cock
control
drain
duct
energy
engineering
equipment
factory
faucet
fuel
gas
gasoline
gauge
glyph
hydrant
illustration
industrial
industrial valve
industry
manometer
measure
measurement
mechanical
meter
petrol
petroleum
pipe
pipe line
pipeline
piping
plumbing
pressure
production
pump
refinery
sanitary
set
sign
steel
symbol
system
tap
tool
tube
valve
valve icons
water tap