arrow
automotive
caution
conduit
connect
connection
danger
emergency
equipment
extinguish
fire
flange
flow
hazard
hose
hydrant
industrial
industry
instrument
intricate
iron
line
measurement
metal
meter
motor
old
pipe
power
protect
protection
red
rescue
safe
safety
security
sprinkler
steel
stopcock
supply
system
technology
tool
tube
utility
valve
wall
warning
water