actuator
alarm
alignment
arrow
bell
caution
colorful
concrete
conduit
connection
crisscross
emergency
equipment
faucet
fighting
fire
firefighting
fittings
flange
flow
gage
hazard
hose
industry
instrument
intricate
joint
line
measurement
meter
parallel
pipe
pipeline
red
resources
row
safety
sprinkler
stopcock
supply
system
tap
technology
tube
utility
valve
wall
warning