I just bought a gravely ztr 44 inch and my very first time I took out a back flow valve. It came up 3 ft off the ground. I am new to using the Ztr but I first went byt it I said to myself don't hit that thing and then I hit the darn thing and water went gushing. I quickly turned off the water and went to the irrigation store and bought everything I needed. It was schedule 80 pipe and cost me 43.00 dollars. Any way the customer was happy I fixed it and now I got the hang of this gravely. He did mumble at first "not a good start" But this is the first and last time I do that. In my first week I did land 6 new lawns as well.