Water heater dip tube

Abstract

A water heater dip tube includes an elongated body having an inlet end and an outlet end. An inner volume is arranged within the elongated body. An anti-siphon orifice is arranged along the elongated body proximate the inlet end. The anti-siphon orifice extends through a wall of the elongated body. The dip tube further includes an elastomeric membrane secured to the elongated body. The elastomeric membrane is arranged in the vicinity of the anti-siphon orifice. The elastomeric membrane is operable to block fluid flow through the anti-siphon orifice when a pressure at the inlet end is greater than a pressure at the exterior of the dip tube adjacent to the anti-siphon orifice, and to allow fluid flow through the anti-siphon orifice when a pressure at the inlet end is less than a pressure at the exterior of the dip tube adjacent to the anti-siphon orifice.

What is claimed is: 
     
         1 . A water heater dip tube comprising:
 an elongated body having an inlet end and an outlet end;   an inner volume arranged within the elongated body and providing a fluid flow path extending through the inner volume between the inlet end and the outlet end;   an anti-siphon orifice arranged along the elongated body proximate the inlet end and extending through a wall of the elongated body; and   a flow channel forming part of the inner volume and connecting the anti-siphon orifice to a remainder of the inner volume,   wherein the flow channel is not along the fluid flow path and is configured to prevent flow through the anti-siphon orifice when fluid is flowing along the fluid flow path from the inlet end to the outlet end and to allow fluid flow through the anti-siphon orifice in the absence of fluid flow along the fluid flow path from the inlet end to the outlet end.   
     
     
         2 . The water heater dip tube of  claim 1 , further comprising an insert arranged at least partially within the inner volume, the insert having a first end located between the inlet end and the anti-siphon orifice and a second end located between the outlet end and the anti-siphon orifice. 
     
     
         3 . The water heater dip tube of  claim 2 , wherein the insert is arranged completely within the inner volume. 
     
     
         4 . The water heater dip tube of  claim 2 , wherein the insert includes an engaging member arranged between the anti-siphon orifice and the first end. 
     
     
         5 . The water heater dip tube of  claim 4 , wherein the engaging member is one of a plurality of engaging members. 
     
     
         6 . The water heater dip tube of  claim 4 , wherein the engaging member is positioned on a first section of the insert, and
 wherein the insert includes a second section, the second section extending from the first section along a central axis of the water heater dip tube, past the anti-siphon orifice, to the second end.   
     
     
         7 . The water heater dip tube of  claim 6 , wherein the flow channel extends from the anti-siphon orifice, between the second section and an inner surface of the elongated body, and to the remainder of the inner volume. 
     
     
         8 . The water heater dip tube of  claim 1 , wherein the flow channel is an annulus. 
     
     
         9 . The water heater dip tube of  claim 1 , wherein the elongated body includes a first body portion and a second body portion, the second body portion being joined to the first body portion to form the flow channel. 
     
     
         10 . The water heater dip tube of  claim 9 , wherein the outlet end and the anti-siphon orifice are provided by the first body portion. 
     
     
         11 . The water heater dip tube of  claim 10 , wherein the elongated body further comprises a third body portion joined to one of the first body portion and the second body portion, and wherein the inlet end is provided by the third body portion. 
     
     
         12 . A water heater dip tube comprising:
 a first body portion providing an inlet end of the dip tube;   a second body portion providing an outlet end of the dip tube;   an insert joined to the first body portion and the second body portion, a first end of the insert being received within the first body portion and a second end of the insert being received within the second body portion; and   an anti-siphon orifice extending through a wall of the second body portion, wherein the anti-siphon orifice is located at a first distance from the inlet end and wherein the second end of the insert extends to a second distance from the inlet end, the second distance being greater than the first distance.   
     
     
         13 . The water heater dip tube of  claim 12 , wherein the insert comprises at least one first engaging member configured to engage at least one corresponding hole in the first body portion. 
     
     
         14 . The water heater dip tube of  claim 13 , wherein the insert further comprises:
 an annular flange separating the first body portion from the second body portion; and   at least one second engaging member configured to engage at least one corresponding hole in the second body portion, the at least one first engaging member and the at least one second engaging member positioned on opposite sides of the annular flange.   
     
     
         15 . The water heater dip tube of  claim 13 , wherein the insert further comprises:
 a first section, the at least one first engaging member being positioned on the first section; and   a second section extending from the first section along a central axis of the water heater dip tube, wherein the first section defines a first outer diameter and the second section defines a second outer diameter that is smaller than the first outer diameter.   
     
     
         16 . The water heater dip tube of  claim 14 , wherein the insert further comprises:
 a first section, the at least one first engaging member and the at least one second engaging member being positioned on the first section; and   a second section, the second section extending from the first section along a central axis of the water heater dip tube, past the anti-siphon orifice, wherein the first section has a first outer diameter and the second section has a second outer diameter that is smaller than the first outer diameter.   
     
     
         17 . The water heater dip tube of  claim 16 , wherein a flow channel extends from the anti-siphon orifice, between the second section and an inner surface of the second body portion, and to the second end of the insert. 
     
     
         18 . The water heater dip tube of  claim 17 , wherein the flow channel is annular. 
     
     
         19 . The water heater dip tube of  claim 12 , wherein the insert comprises:
 an annular flange separating the first body portion from the second body portion;   a first section extending from the annular flange to the first end of the insert; and   a second section extending from the annular flange to the second end of the insert, wherein the second section at least partially defines a flow channel in communication with the anti-siphon orifice.   
     
     
         20 . The water heater dip tube of  claim 19 , wherein the flow channel is partially defined by the wall of the second body portion.