# Question about order of components in drip system.



## garya505 (Jun 24, 2021)

I have a question about the order of components in drip system.

Abbreviations:
PRF = Rainbird PRF-075-RBY Pressure Reducing Filter
AVB = Orbit 51059 Atmospheric Vacuum Breaker
ZoneValve = Rainbird 075DV or 100DV

I have an existing system that I am adding 2 zones to, for drip irrigation only. The existing system has a main shutoff valve followed by filter (RainBird RBY-075-200MX) and a master valve (Rainbird DVF). After the master valve, the line then has a "tee" to the existing front yard drip system and the backyard.
MainShutOffValve->MainFilter->MasterValve->MainTee

The front yard drip system (zone 1) has a zone valve (100DV) followed by an AVB (Orbit 51059 Atmospheric Vacuum Breaker) and then a PRF (Rainbird PRF075RBY Pressure Reducing Filter). This system works fine and will not be changed.
MainTee->ZoneValve1->AVB->PRF

The backyard is what I am adding now. I will tee the line for 2 more zones (zone 2 and 3). I will use Rainbird 075DV or 100DV valves and PRF (Rainbird PRF-075-RBY Pressure Reducing Filter). I will also have an AVB (Orbit 51059 Atmospheric Vacuum Breaker) on each zone. I understand that the AVB must be after the valve. My question is regarding the the order of the PRF and AVB on each backyard zone.
1. MainTee->BackyardTee->ZoneValve2->PRF->AVB (this is the order I would like to use because it's easier)
2. MainTee->BackyardTee->ZoneValve3->AVB->PRF (this is the order on the front yard zone)

So, the basic question is, does it matter if the AVB is before or after the PRF? If one of the above is better, then why? If option 1 is acceptable, I might use the Rainbird XCZ-075-PRF combo kit.


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## MasterMech (Sep 24, 2017)

Is it possible for the AVB to suck in debris? This may be why it was installed in front of the filter previously.


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