I have a 2" abs pipe in the basement connecting the sink,watersoftener and the 2" copper pipe coming from the main floor, it is routed awkward and I didn't see reason why it is connected, friend of mine told me that this is vent to prevent ground pressure! Not sure what he mean by this, the house is abour 40-50 years old, can I cut this pipe?

friend of mine told me that this is vent to prevent ground pressure! Not sure what he mean by this,And neither do I. A vent is used to relieve the vacume caused by draining water. Before I tell you to cut the pipe coming from the main floor you have to tell me exactly what it id and what it does. Back to you, Tom