A 2 1/4" flange is bolted to the bottom of the base. It is held on by carriage bolts that are also used to hold the straps for the tank (set up in a similiar manner as the tank for my test stand for the glow fuel engines - see above posts). The flange is used for threading the test stand onto a 38" x 2 1/4" galvanized pipe. I have another pipe cemented into the ground out side (in a gravel area so as not to kill any lawn with spilled gass!). This pipe is about 24" to 30" deep and is capped off at ground level when not in use. When I want to use the test stand, the cap is removed and the 38" pipe is connected to the pipe in the ground with a 2 1/4" threaded coupler.

This stand is probably a lot beefier than it needs to be, but I did want something durable.