Backflow preventer: basement usage?

[ajcrm125]

I've been reading online the use of backflow preventers for irrigation systems and often read that one of the benefits of using a Double-Check Backflow Preventer is that it can be placed below the height of the highest head in the system, making it applicable for underground or basement usage.

I decided to get the Febco FE850-100. However when looking at the installation material it mentions that the typical installation has it 12" higher than the ground.

http://www.sprinklerwarehouse.com/v...ges/Backflow_Diagram_jpgs/DCA/febco_850_1.jpg

So what's the consensus? Can these be used for basement applications?

Thanks!
-Adam

 

[WorthFlorida]

Use this style for below grade. The type above uses test cocks that needs to be above grade. Most municipalities requires a once a year back-flow test on commercial properties from the "city" water supply to the building.

https://www.homedepot.com/s/double%20check%20valves?NCNI-5

https://www.zurn.com/media-library/web_documents/pdfs/installation/is950xlt-pdf