"My airgap on my sink keeps spitting water every time that I run our dishwasher. What is wrong?"
Quality made air gaps are pretty basic products that rarely go "bad". If you purchased your airgap from us you can rest assured that it is a quality airgap. IF your air gap didn't spit in the past then try running your garbage disposer for a few minutes. Basically the way your dishwasher airgap works is that water is pumped through the smaller side of the airgap (5/8") into the airgap and then gravity takes it to your sink (or disposer) with larger hose (7/8"). The larger size has an area of about twice as large and with gravity there normally isn't any problem. If the 7/8" hose is sagging or there is grease build up or a partial stoppage or blockage in your sink/disposer the airgap can "spit." After inspecting under the sink to make sure the 7/8" isn't kinked or going up hill at all (it has to go smoothly downhill all the way) then disconnect the 7/8" hose at the sink/disposer and point it into a large bucket. Then run the dishwasher and see if the airgap still spits. If it does then you know you need a new airgap and if it doesn't then you know the "problem" is after the hose.

"What are the sizes on the inlet and outlet of the dishwasher air gaps?"
Standard 5/8" for the inlet and 7/8" for the outlet.

"Will your softener air gap fit the discharge line from my softener?"
It is designed for the softeners that we sell as well as most large softeners. It is for 1/2" i.d. hose, which is the same size as the discharge on our softeners. The 90-degree connection can be installed in any direction and you simply glue it into place once you are happy with the setup.

"It says that the water softener air gap fits a 2" standpipe. Please explain a little better.?"
The air gap is designed to fit inside of a 2" standard (schedule 40) PVC pipe or ABS pipe. It's best to glue it into place with a multipurpose glue for PVC/ABS plastic, but many people have simply installed into their plastic pipe and not glued it. It also will fit inside most steel or cast iron standpipes (a standpipe is the pipe that is for clothes washers). If you have a 1 1/2" standpipe this air gap can work but it is more trouble to install and you'll need 2" pipe, and a 2" x 1 1/2" coupling or the easiest way to install this softener air gap onto a 1 1/2" standpipe is to order our special coupling (order #AIR-COUPLING $7.18 ) that has a stainless steel clamp to attach onto a 1 1/2" pipe.