My old anti-siphon vacuum breaker (NIBCO model 90) finally broke and leaked water after I forgot to remove the hose hooked to my outside wall faucet last winter. The cap of that breaker isn't threaded; it simply lock-click in place by pushing it down. It figures that the cap is not airtight (perhaps no pressure build-up).
The cap of the replacement kit (MUELLER STREAMLINE model# 888-183 SKU# 113898) I bought from HomeDepot (and installed) is threaded. I needed to make clockwise turns to put it in place.
Being threaded (perhaps airtight and could cause pressure build up), my question is: did I make the appropriate replacement?
Both old and new caps are made of sturdy plastic material (or fiberglass, perhaps). I should also note for clarity that the anti-siphon assembly that seats inside the plumbing are threaded in both the old and the new. They are fairly matched. I'm only asking about the difference in the cap (external visible cover of the anti-siphon vacuum breaker kit/assembly).