Use a 3/8″ parallel booster line if you have more than 35 nozzles in series on a run.
In general, the booster line should run from just outside the unit and reconnect with the 1/4″ run at it’s halfway point. So, if you need to boost a 600’/60 nozzle run, do it with 300′ of 3/8″ line.
The components and their part numbers are shown below.
As close as possible to the unit, splice a tee into the 1/4″ nozzle run. Then use a very short piece of 1/4″ tubing, a 3/8″ x 1/4″ reducer plug, and either a 3/8″ union elbow or union coupling to connect the 3/8″ boost line as shown below. Reconnect the booster line to the 1/4″ run at the halfway point with the same components.
See all the Pressure Engineering Rules