Your skid in all probability already has a float tank built in. If it doesn't it should. The float tank is a small resevoir that helps prevent your pump from running dry. It is also a great place to modify your machine so that when you stop spraying and the machine goes into bypass the water goes back into the float tank instead of back into the pump. Ther are some diagrams posted here in this forum with directions (try the search function)
The Hydro Tek 8 gpm machine does not come with a float tank. It is designed to draw from a water holding tank (125 gal & up). Most float valves are rated at 8 gpm max, except for the Hudson valve, but you're relying heavily on your customer's source delivering 8 gpm. Sometimes they will, sometimes not.
If you have a water tank you can not use a float tank too. It just won.t work.
One or the other.
Now if the water tank was out of the picture the only reasons for a float tank is so you can draw soap at high pressure and it provides a siphon break so the water from the pressure washer does not go back into the city water supply.. That is it in a nut shell.