Vented Sink Tailpiece

Abstract

A vented tailpiece that may be used in existing sink installations is connected to a sink drain and a drainline trap as part of the sink drain line. A vent in the tailpiece releases air upstream of the drainline trap as the air is displaced by liquid flowing through the drain line. A retainer connected to the vent catches liquid escaping through the vent. The retainer may be fitted with an extension if necessary. An overflow valve, which is preferably a float valve, may be attached to the retainer and configured to prevent liquid from spilling out of the retainer if a problem in the drain line causes liquid to back up into the retainer.

1 . A tailpiece for installation in a sink drain line between a sink drain and a drainline trap, the tailpiece comprising:
 a) a pipe having a top end positioned to receive liquid flowing through the sink drain and a bottom end that attaches to the drainline trap; and   b) a vent in the pipe between the top end and the bottom end.   
   
   
       2 . The tailpiece of  claim 1  further comprising a retainer attached to the pipe over the vent such that the retainer deflects liquid passing out of the vent back into the pipe through the vent. 
   
   
       3 . The tailpiece of  claim 2  wherein the retainer comprises an open end for releasing air that escapes through the vent. 
   
   
       4 . The tailpiece of  claim 3  wherein the retainer is permanently attached to the pipe. 
   
   
       5 . The tailpiece of  claim 4  wherein the pipe and retainer are metal, and wherein the retainer is welded to the pipe. 
   
   
       6 . The tailpiece of  claim 4  wherein the pipe and retainer are plastic, and wherein the retainer is adhered to the pipe with a waterproof adhesive. 
   
   
       7 . The tailpiece of  claim 4  wherein the retainer is integral with the pipe. 
   
   
       8 . The tailpiece of  claim 3  wherein the retainer is semi-cylindrical. 
   
   
       9 . The tailpiece of  claim 8  wherein the retainer has a rounded bottom that is attached to the pipe at the bottom of the vent. 
   
   
       10 . The tailpiece of  claim 3  further comprising an extension tube attached to the retainer at the open end. 
   
   
       11 . The tailpiece of  claim 10  wherein the extension tube is flexible. 
   
   
       12 . The tailpiece of  claim 10  wherein the extension tube extends above the fill line of the sink. 
   
   
       13 . The tailpiece of  claim 3  further comprising an overflow valve attached to the retainer at its open end. 
   
   
       14 . The tailpiece of  claim 13  wherein the overflow valve comprises:
 a) a housing attached to the retainer;   b) one or more vent holes in the housing that allow air to escape; and   c) a float positioned inside the housing that floats on the surface of liquid in the housing and covers the vent holes if the housing fills with liquid.   
   
   
       15 . The tailpiece of  claim 13  wherein the retainer comprises an angled portion and a vertical portion attached to the angled portion, the overflow valve being attached to the vertical portion. 
   
   
       16 . The tailpiece of  claim 15  wherein the retainer is a tube. 
   
   
       17 . The tailpiece of  claim 16  wherein the angled portion is permanently attached to the pipe, surrounding the vent. 
   
   
       18 . The tailpiece of  claim 16  wherein the retainer is removably attached to the pipe. 
   
   
       19 . The tailpiece of  claim 18  wherein:
 a) the pipe further comprises a threaded bulkhead that surrounds the vent; and   b) the retainer further comprises a threaded portion attached to the angled portion, the threaded portion having threads that are mated to the threads on the bulkhead.   
   
   
       20 . A tailpiece for installation in a sink drain line between a sink drain and a drainline trap, the tailpiece comprising:
 a) a metal pipe having a top end positioned to receive liquid flowing through the sink drain and a bottom end that attaches to the drainline trap;   b) a substantially circular vent in the pipe between the top end and the bottom end; and   c) a semi-cylindrical metal retainer welded to the pipe over the vent, such that the retainer deflects liquid passing out of the pipe through the vent back into the pipe, the metal retainer having a rounded bottom attached to the pipe at the bottom of the vent.