Originally Posted by Murphie
...Has anyone bought or used the new drain attachment that replaces the p trap under your sink? It frees up space under the sink so you can get at the pots stored in the back behind all the plumbing...
Actually, they have been around for a while. I haven't used them but they violate most stick and brick plumbing codes. All mechanical drain devices will fail sooner or later, including the AAVs under the sinks that are often used in RVs to replace an actual vent. Since the drain valves are actually exposed to water and anything carried in the water, they are even more prone to failure than the AAVs. The drain valves may be the only way to get something to fit in a retrofit, however. If you decide to replace the trap with a drain valve, i would get an extra one so you can swap it out quickly when it fails since they can be a little hard to find locally.