what are you using for z pipes, the pipe that connects the underground pvc gasketed pipe to the pivot tower? They have a 45 top and bottom. Also, how do you anchor them in the ground to keep them from coming apart at the joint? thanks.
what are you using for z pipes, the pipe that connects the underground pvc gasketed pipe to the pivot tower?
Around here, they just get a lenth of steel pipe, and bevel cut the pipe to the angle they want (many are custom angles here, to compensate for slope. To get the angle you want, just cut it on a bandsaw set at half the angle you need, rotate a half turn, and weld it.) You just weld whatever ends on it, that you need, they are available at irrigation shops. If you don't trust your welding, any competent blacksmith shop can do it.
They have a 45 top and bottom. Also, how do you anchor them in the ground to keep them from coming apart at the joint?
After your pipeline is strung out in the bottom of the trench, and everything looks good, dig the loose dirt from around the bottom of the Z pipe, to the end of the trench. The backhoe guy should have made the trench just a foot or two longer than it needed to be, at the bottom, until you hit undisturbed ground. WIth all the loose dirt removed, pour a little concrete in the bottom to fill the gap between the bottom of the Z pipe, and the end of the trench. Some guys weld 'ears' on the bottom of the Z, to better secure it. They don't have to be very big, just enough to anchor the concrete.
Often, a little 'dam' is made in the bottom of the trench, so the concrete doesn't try to flow down the trench. The goal is to leave access to the end of the Z, so that the plastic pipe can be replaced without breaking the concrete.
Many people also put some sort of rustproofing on the pipe, at minimum from a little above the ground, to at least a couple feet down.