Some useful comments here, especially by Duncan Brown, Deadalus & doug293cz.
Also, here's my experience with getting & using Beer Gas in the NW for many years.
Use same regulator as CO2, CGA320 - that's fitting my local AirGas has on BEER GAS tanks.
75% Nitrogen 20% CO2 & that's the ratio Guinness recommends. 70/30 is probably fine.
No problem with your
[email protected] regulator as long as high side gauge reads at least 3000 psi.
You won't get an exchange BEER GAS (or Nitrogen) tank that has higher pressure than that.
You can slowly carbonate your home brew with BG and it won't overcarb due to the ratio.
A Guinness commercial keg comes with 1.2 volume CO2. That's what keeps the fizz/taste.
Lots of different opinions on Guinness dispense pressure. But, yes - temp, line length etc matter.
The "Cascading" effect & latte colored pour is caused by HIGH pressure forcing liquid thru the five tiny holes in a special Guinness/Stout tap. (See pic) IF THE BEER HAS TOO MUCH CO2 IN THE KEG IT WILL FOAM LIKE CRAZY. *** BUT, here's an interesting fact. I've done this many times. ***
You CAN dispense a great Stout/Cascading/latte colored pour thru a Guinness tap
with CO2 *** IF & THIS IS THE BIG IF:
You momentarily turn the CO2 pressure way up to 20-30 psi ONLY for the pour *** THEN IMMEDIATELY TURN IT BACK DOWN. If you forget, the beer will quickly over carbonate. BUT IT WORKS GREAT IF YOU REMEMBER!
Here's another favorite trick of mine. Use paintball tanks! Get PAINTBALL TANKS. (cheap on CL or even new) CO2 PB tanks are rated at 3000psi. Cheap, light, fit in the fridge, easy to take to a party. I use a High Pressure Air (HPA) 4500psi tank for Beer Gas. Pretty easy to make or buy a refill "station" to refill them from an upside-down CO2 tank (unless you have a tank with a syphon tube to the liquid gas on the bottom) And you'll never lose a whole tank of CO2 or Beer Gas overnight to a small leak.
Pic of Guinness tap parts - 2nd pic is title of great info you can download from Brewers Assoc