The best replacement for valves is circulators.

The best alternatives to valves are rated as following:
★★★★★  circulators
★★★★  transistors
★★★  ball valves
★★  tubes
★★  4 valves
★★  gate valves
★  rings
★  butterfly valves
★  globe valves
★  circulators pumps
★  schrader valves
★  dished
★  av valves
  cast valves
  tissue valves
  semilunar valves
  lifters
  stainless steel valves
  supertech
  arteries
  flashback arrestors
  proportional valves
  supertech flat faced valves
  mechanical valves
  24 volt valves
  schrader
  24 valves
  2.02
  8mm valves
  spool valves
  cylinders

Your alternative for valves is not listed? Suggest!
Speaking about valves, one probably shouldn't forget about actuators.

Other search terms related to valves and their ratings are:
★★★★★ actuators
★ tornado alley horns
You have in mind a companion for valves and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of valves in all years. Click on graph for more.
valves
circulators
transistors