You are not logged in.

Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.




Tuesday, September 22nd 2009, 1:21am

Are RPZ's safe?

Is it safe to run a fertilizer injector with a RPZ (Reduced Pressure) backflow as the protection? Can any of the chemical "leach" past the device? Is it safer to have a "air gap" between the fertilizer system and the potable water source?



Supreme Member


Tuesday, September 22nd 2009, 2:18am

RPZs are designed for "high hazard use":

As I understand it, they are designed in such a way that it's fail-safe mode is to discharge water out a discharge port on the unit before it allows any hazardous water to back flow into the potable water supply.

The only known failure that will allow an RPZ to cross-contaminate the water supply is if the unit becomes submerged. As such, RPZs can not be installed below grade.


Supreme Member

Posts: 482

Location: Houston, Texas


Tuesday, September 22nd 2009, 12:08pm

It is safe and designed for this type of use

High Hazard applications like this should have the RP inspected by a Licensed Back Flow Prevention Assembly Tester annually. This is the only way to understand if the device is working. Looking at the device installation is not an indication of proper working of the device. Many brand new units can fail due to turning on the water too fast and dislodging a spring or seal. Trash or glue or pipe shavings can also cause a unit to fail upon installation. I would also recommend that you watch the test because it can be interesting to watch.

Dan :thumbsup:

It also prevents the (PAPER PUSH) from less morally responsible testers :cursing:
:thumbup: :thumbsup:
LI0006121, BPAT0011021, CI0009500


Starting Member


Friday, March 19th 2010, 4:41am

It maybe safe.

Sprinklers have to be installed very carefully and any problems while installing have to be immediately repaired.Not quite sure about the backflow devices though.

Rate this thread