Basically the pipe has a window in it partially covered with a sliding 'shutter'- you need to loosen a screw to slide this. If you open the window wider, you will get more air and bluer flame, but you don't want so much air that the flame burns noisy, or the blue inner cone lifts. If you close the window, you cut the air, and it burns with a lazy flame, with more orange tips. This is not a clean burn, so you need to open the shutter just a little.

The great thing about the 22k burners is the flame coverage on the bottom of the pot/pan. I can't remember if the 15k has the same flame pattern as the 22k but the 22k is great for large bottom pans due to the having flames all the way to the tips of the star. I even like to simmer on the 22k's better as they heat the bottom of the pan more evenly. I usually only use the 8k if I'm using a really small pan and saucing. I LOVE searing meat on 22K Hi, cranking up the 1200 cfm fan and watching the smoke roll, it's a site to behold. Also I'm an avid woker, sometimes I pull the grate sometime I don't. If I want to move the pan a lot I leave the grate on, if I'm just going to stir I'll take it out, it's hard to shake the pan when it's in the well below the grate. 15k is my overflow burner, I also have a griddle and like ctycdm, it's covers probably 50% of our usage, it's great for keeping sauces warm and can be used like a FT if needed.

Thanks for all the input. I may be mistaken about 2 simmers. All I know is the 2 back outside rear burners look aloke to me Star pattern , but the holes for the flames are just in the circle part and not in the arms (like the points on a starfish) I'm assuming these are the 2 simmer ones. The one in the center rear has the center ring of holes plus a single row of holes on the arms so I assume this is the 15 k. The 2 front burners are the same but have a double row of holes in the arms so I assume these are the 22k. If I could replace one of the 2 rears with a 15k , then I might be able to buy a add on griddle and have fairly equal heat used over those 2 burners. All that said we are really pleased with it , and if looks could kill , it would ! I bought a 42" vent hood off ebay that looks great and has performed well . We have not yet had all burners going at once . Admittedly it is not as powerful as most of the ones mentioned here , but at around $500 it is serving the purpose. It definitely does not look inexpensive. I'll try to post some pictures of the install . The wife is very happy with her kitchen.

The 22k and 18k burner heads are identical. The former has more power because it's brass orifice behind the knobs has a slightly larger hole to allow more gas to flow through. You could theoretically drill a slightly larger hole into the orifice on the 18k burner. It would have to be a VERY precise drilling though bc the difference between the two is barely noticeable to the naked eye. Disclaimer: I I haven't done it nor would I recommend it bc the calibration would never be identical to the factory drilled ones. And I'm sure doing it would void your warranty and possibly your home owners insurance. Thus, what might be better is searching online for a speciality part retailer that sells the larger orifice.