Noun
needle valve (plural needle valves)
A type of valve having a small orifice and a needle-like plunger, allowing precise regulation of generally small flow rates.
Increasing the amount of fuel gas flow through the tube by opening the needle valve will increase the size of the flame. Source: Internet
The flame also burns without noise, unlike the Bunsen or Teclu burners. citation * Tirrill burner – The base of the burner has a needle valve which allows the regulation of gas intake directly from the Burner, rather than from the gas source. Source: Internet
The fuel is sprayed with the help of a nozzle that is opened and closed with a needle valve, operated with a solenoid. Source: Internet