https://www.amazon.com/DerBlue-pressure-Anti-Drip-clogging-Nozzles,ceramic/dp/B01HYA1SBI/ref=sr_1_3?ie=UTF8&qid=1478813647&sr=8-3&keywords=anti+drip+nozzleThe brass anti drips are typically 75psi open, 35psi close for the low pressure version and 145psi open, 70psi close for the high pressure version.
The high pressure nozzles have much higher gate pressures than that. These are made for use at 1000psi and their minimum operation pressure is nearly 600. I'm sure there is variance between manufacturers but most of them report the activation pressure on the HP ones as several hundred psi. They are way outside of what we have reason to use.
-Eskander