Mr Volcano Burner!

[Frosty]

The reason you needed to ask the question is because you do not understand the relevance nor Mike's answer. The short answer to your latest question is Y E S. 

Jet diameter produces a specific volume at a specific velocity for a specific psi. It does NOT regulate anything. ALL regulatory controls are before it in the fuel circuit.

A needle valve regulates volume not psi exactly like the needle valves in a carburetor. 

A 1/4 turn shut off valve is an on/off control. Using it to regulate the burner provides seriously poor control and worse they are NOT designed for a restricting a flow. Doing so erodes the seats and before long it won't even turn the flow off AT ALL. ON OFF is the ONLY thing they are suited for. That does NOT mean you shouldn't open them slowly to light your forge say over a period of 1-1.5 seconds to prevent blowing the ignition source out of the forge and allowing the flame to settle down.

If you build a low velocity burner a needle valve is a waste of money, low velocity controls very well with psi.

Needle valves are excellent fine controls for high velocity burners, and sometimes necessary.

Try not to nit pick answers to your questions it irritates the folk you want to ask.

Frosty The Lucky.

 

 

[Mikey98118]

52 minutes ago, Frosty said:

If you build a low velocity burner a needle valve is a waste of money, low velocity controls very well with psi.

Needle valves are excellent fine controls for high velocity burners, and sometimes necessary.

Good point, and counterpoint. I always use needle valves on my high velocity burners; but is for fine control at my fingertips, rather than necessity. Regulators are all that is necessary; needle valves are just a luxury