The addition of a pressure tank to an irrigation system will help solve many problems. The tank will help to stop short cycling of the pump, erratic pressure changes, and low flow problems. The tank helps stop all of these issues by supplying a buffer between the water supply and water distribution ends of the system. The installation of the tank requires very little to be done correctly.
Shut off the power and water supplies to the system. This helps make sure the system will not turn on when the system is drained.
Drain the water from the system. Most likely, if there is no tank installed, the system self-drains after each use. Be sure to check.
Cut the supply pipe between the water supply and the distribution valve. The cut should be made where the tank will reside.
Install the pipe tee at the location of the pipe cut. Install the tee per the requirements of the pipe.
Install the 1-foot of pipe to the tee side of the tee. This will be the pipe to the tank.
Attach the tank the the pipe. Some tanks may require more pipe to complete the connection.
Reconnect the water and power supplies. Test the system for leaks.