Posted by Gary Swart on August 06, 2004 at 17:47:36:
In Reply to: Re: Washing Machine posted by LonnythePlumber on August 06, 2004 at 17:06:23:
I don't know about "common", but I replaced an ancient flap-type check valve in my basement with a PVC drain fixture that has a float ball that will seal off rising water. The flap on the old one become fouled with lint and dirt, and on two occasions the city sewer backed up very slowly and flooded my basement. The I think this style check valve will prevent my basement from flooding at least until the city sewer backup reaches toilet level. The backups were caused by grease from a fast food resturant's grease trap failure collecting and congealing in the manhole where my sewer empties.