Pressure gauge in Beginners Place Posted September 12, 2019 On a Venturi burner, knowing the pressure is useful, rather than essential, mainly to allow the operator to start the forge, set it to where it was last time it did the same job, and get on with something else while it gets to temperature. I always used to fit a gauge at the mixer (and still do when I want other folk to see what is happening with the burner), but now use plugged welding regulators on my forges. These have graduations marked on the body so that the skirt of the adjusting knob shows the pressure they are set to. They have the advantage of being built "industrial", with a nice big adjusting knob intended for use by someone wearing heavy welding gloves. It sounds like a pretty crude way of knowing the pressure, but there are not many gauges that provide significantly more accuracy/repeatability at reasonable cost. I like to keep all of my controls at the gas cylinder end: it's the direction I head if things start going wrong and I don't want to introduce the need to make an extra decision while the midden is hitting the windmill. I'm also not keen on adding weight to the end of the burner. There are various different gauges available. As said, very few will offer good accuracy at anything like reasonable cost. I tend to use glycerine-filled gauges with 1/4" bottom connections. These have stainless steel cases with sufficient structural integrity to contain the glycerine and the 1/4" connection is a lot harder to break than a 1/8" one. I have seen 1/8" back-entry gauges, salvaged from the regulators of old compressors, fitted on burners and try to keep my distance. If I *really* want to know what the pressure is doing, I use a 4-20 mA pressure transmitter and a datalogger, but I'm probably a little more anal than most smiths. It is worth pointing out that gas flow through a jet does not vary linearly with pressure, but as the square root of the pressure. If you want to double the gas flow, you need 4 times the pressure. Doubling the pressure will give 1.41 times the gas flow and halving it will give 0.707 times the gas flow. If you want to spend money to find out what is happening with your forge, you will almost certainly get more bang for your buck by investing it in a decent thermocouple and pyrometer.