Sprinkler System Components Problem Adding Drip Irrigation To Existing Sprinkler System?

Problem adding drip irrigation to existing sprinkler system? - sprinkler system components

I am a beginner and I try to add a drop in an irrigation system that waters my garden. This system has a siphon vacuum valve and it is expected to use it. I'm going to Home Depot and has a Y-filter, pressure regulator, 3 / 4 "to 1 / 2 swivel connector and 1 / 2 inch pipe.
Well, anti-siphon valve is only a few inches above the ground. And if I play the 3 is primarily about 9.10 inches long, should I have one foot or more in the anti-siphon dig code first to be involved?
(I've already done this, but something tells me that I could be wrong.)

Is it necessary to apply the PVC glue screw things in different components? (It seems that if there is leakage, as they touch. Esp joint Yy filter pressure regulator and the relationship between the regulator connector rotating pressure)

Thank you very much!
Vivek