Vented drain lines under sink. Do they need to be there?

[Maineman]

I am in the process of remodeling the kitchen and bathrooms. The drain pipes under the sink both have spring loaded vents in them. Apparently the vaccume caused by the draining water pulls against the spring and lets air into the system. Am asking because none of the other houses I have lived in or worked on had these vents. This is our first MH so don't know if these vents are just a MH thing and don't need to be replaced.

Thanks,

Tom

[Greg]

Tom, They have been used in mobiles for years, a few stick built homes use them. You do need vents for the drains, If you are doing a remodel you COULD run vents through the roof - but be warned you are opening up the roof for a potential leak. Greg

[Maineman]

Thanks,

I just got the same feedback from another do-it-yourself web site and Home Depot. We do have a stack vent that goes through the roof but apparently that is not enough venting for the way the plumbing was installed. Didn't know they would fail over time. The one I have looks good so will reuse it. Should it fail I can unscrew the old one and screw in a new one. HD has them for $7.

Thanks again,

Tom