Bronze Vented Loops
A vented loop keeps fluids from siphoning from tank to tank. The valve in the top of the loop allows air to enter the line when not in use and seals when water or other fluid passes through. Using a vented loop within sanitation or engine exhaust plumbing allows air to enter to break siphon, but does not permit air and odors to escape into cabin or engine room.
These vented loops are cast in bronze and are precision-machined. Each is sold complete with joker valve.
Spare vent valves, made of durable plastic with rubber gasket, are also sold separately: