V-traps are designed to make P-traps obsolete. The unique valve design of the V-traps makes them virtually trouble free. They are self-priming; you never have to add water to make them work. A self-sealing column of water, equal in height to the negative pressure in the air conditioner, automatically prevents air from entering the drain trap allowing the condensate to drain freely. The column of water empties with each air conditioner cycle along with accumulated dirt and debris.

Temperature Control Services LLC
http://vtraps.com/
724-650-8178