Cure for Airlocks In Waste Pipes

[Dipper65]

My first post on here and though it was about time I stopped lurking and made a contribution. The kitchen sink on our Autosleeper van conversion was very slow to drain and after cleaning and replacing the original restrictive tank connector with a full bore 28mm there was no improvement, looking under the van I could see there was part of the hose that had to drop under the chassis member and then rise again to connect to the tank creating an airlock. I did a lot of searching and eventually found a US thing called a loop vent. Using John Guest 28mm to 15 Tee, a 15 to 12 reducer and a length of semi rigid pipe to loop and vent outside under the floor has made a vast improvement to the flow?

 

[Richard n Ann]

 

[Lenny HB]