Plastic threaded inserts glue into thin PVC. They work in product photos. They often weep once the tank is full and the thread load is real.
What brass + O-rings change
Brass seats predictably against PVC when torqued correctly. Twin O-rings give you a inspectable seal line — not “hope the adhesive holds.”
What we test
Each Loavara outlet batch is bench-checked to 150 PSI before packing. On your yard, the meaningful test is simpler: full barrel, hose attached, five minutes, dry fitting.
That is the clip on our founder leak-test page — the same check we run before a barrel ships.