Anti backflow for sprinkler system

My first one (new build) that was above ground

https://www.nachi.org/forum/attachment.php?attachmentid=202027&d=1528166665

RW
your recent posts are prime examples of why trec licensing does not assure competency & why you should not be performing new construction inspections or possibly any inspections for a fee

Have you been writing up the ones below ground?

Can’t see it but does not appear there is a strainer on that one.