Does UPC 2015 allow hose connections below grade (e.g. in an underground valve box)? Is a regular vacuum breaker sufficient in this situation or is a double check valve needed (typical for sprinklers)?
603.5.17 Potable Water Outlets And Valves. Potable water outlets, freeze-proof yard hydrants, combination stop-and-waste valves, or
other fixtures that incorporate a stop and waste feature that drains
into the ground shall not be installed underground.
A vacuum breaker is not considered a "stop and waste feature" correct?
Related question regarding yard hydrants, which would be an alternative if I can't put a hose connection under ground. Per Table 603.2 "Freeze resistant sanitary yard hydrants" "Such devices are not for use under continuous pressure conditions."
Does this mean a valve is required a before a yard hydrant? i.e. when you close the valve on a hose bib "hose connection vacuum breaker" is no longer subject to operating pressure, however the "freeze resistant sanitary yard hydrant" assembly as a whole technically remains under pressure when you shut off the yard hydrant.
Best Answer
You'd probably need a double check valve like a sprinkler system to put a garden hose connection underground.
For the yard hydrant: Your link says "Frost Proof" which is different than "Freeze resistant". Further your referenced code says " that incorporate a stop and waste feature that drains into the ground". The description for the yard hydrant you have linked says "Unlike conventional hydrants which drain the water into the ground, these use a reservoir below the frost line to contain the water".
I'd argue that either point makes this portion of the code inapplicable but certainly the 2nd portion where it doesn't drain into the ground at all.