I am adding 2 or three zones of drip irrigation onto my standard system. I was planning on using the new Rainbird drip valve/filter/regulator units. For the largest of the zones I have to run a submain from my valve box (which will then divide in two) to go to two small flower beds. The distance from the valve box to each bed is approximately 40' and 75'. My question is: If my water demand for the drip zones will be in the range of 20-50 gallon per hour can I use 1/2" poly with a Y or tee to each bed or should I use something larger?....or possibly 3/4" to the tee and then 1/2" line to each bed?
My water pressure is quite high at the source (at least 70-75 psi). The source is about 100' from the control box where the drip zone valve will be located and the lines to that point are 1". I expect that I won't have problems even if I used 1/2" but since I have to put this in an existing lawn I wanted to do as little damage as possible.