Gravity Drain Valve

Abstract

A drain valve comprises a housing having a housing wall defining an internal flow passage through the housing; and a post held within the flow passage, the post supporting a first valve member, such that the first valve member contacts a valve seat on the housing wall. The post is selectively configurable to accommodate a further valve member within the housing at a location spaced from the first valve member along the internal flow passage, wherein the further valve member contacts a further valve seat on the housing wall.

What is claimed is: 
     
         1 . A drain valve comprising:
 a housing having a housing wall defining an internal flow passage through the housing;   a post held within the flow passage, the post supporting a first valve member, such that the first valve member contacts a valve seat on the housing wall,   wherein the post is selectively configurable to accommodate a further valve member within the housing at a location spaced from the first valve member along the internal flow passage, wherein the further valve member contacts a further valve seat on the housing wall.   
     
     
         2 . The drain valve according to  claim 1 , wherein the post comprises a first engagement formation at one end thereof for mounting the post in the flow passage and a further engagement formation at an opposing end thereof for attachment to a further post, and
 the first valve member is mounted to the post in between the first engagement formation and the second engagement formation.   
     
     
         3 . The drain valve according to  claim 2 , wherein the further post is attached to the further engagement formation, the further post having the further valve member mounted thereon, the post and the further post being coaxially connected together such that the first valve member and the further valve member are spaced along a common axis. 
     
     
         4 . The drain valve according to  claim 1 , wherein the further valve member has a same diameter and a same geometry as the first valve member. 
     
     
         5 . The drain valve according to  claim 1 , wherein at least one of the first valve member and the further valve member comprises a flexible material that is fused or integrally formed with one of the post and the further post, such that the flexible material surrounds the at least one of the post and the further post. 
     
     
         6 . The drain valve according to  claim 1 , wherein at least one of the first valve member and the further valve member is overmolded onto one of the post and the further post. 
     
     
         7 . The drain valve according to  claim 1 , wherein the housing wall comprises a first housing wall portion being annular in form and having one or more engagement formations at a peripheral end thereof for selective attachment of a second housing wall portion thereto such that the first housing wall portion and the second housing wall portion are connectable about a common axis. 
     
     
         8 . The drain valve according to  claim 7 , wherein the first housing wall portion comprises a first valve seat formation and the second housing wall portion comprises a second valve seat formation. 
     
     
         9 . The drain valve according to  claim 7 , wherein each of the first housing wall portion and the second housing wall portion each comprise an internal annular surface, internal annular surfaces being substantially radially aligned when the first housing wall portion and the second housing wall portion are connected, wherein the first valve seat formation and the second valve seat formation each depend radially inwardly from the internal annular surfaces. 
     
     
         10 . The drain valve according to  claim 7 , wherein the first valve seat and the second valve seat depend radially inwardly of respective first housing wall portion and second housing wall portion by a same radial distance. 
     
     
         11 . The drain valve according to  claim 7 , wherein the first housing wall portion and the second housing wall portion are connectable at an interface and a seal gasket is attachable to an outside wall of either or both of the first housing wall portion and the second housing wall portion for sealing the drain valve against a drain wall in use, wherein the seal gasket comprises a plurality of longitudinally spaced apart sealing flanges extending radially therefrom for sealing the drain valve against the drain wall. 
     
     
         12 . The drain valve according to  claim 1 , wherein the post is removably attachable to the housing. 
     
     
         13 . The drain valve according to  claim 1 , wherein the housing comprises at least one strut and the post depends from the at least one strut along a central axis of the internal flow passage. 
     
     
         14 . A drain valve housing comprising:
 a wall surrounding an axis so as to define an internal flow passage through the drain valve housing; and   a strut depending radially inwardly from the wall and arranged to support in use one or more valve members held within the flow passage,   wherein the wall comprises a first wall portion defining a complete annulus of the flow passage and terminating at a peripheral end, the first wall portion having a valve seat between the peripheral end and the strut, the peripheral end having one or more engagement formations for selective attachment of a second housing wall portion thereto, the second housing wall portion extending the axial length of the internal flow passage when attached to the first wall portion.   
     
     
         15 . The drain valve housing according to  claim 14 , wherein the second housing wall portion comprises a further valve seat for use when a plurality of valve members is held within the internal flow passage. 
     
     
         16 . The drain valve housing according to  claim 15 , wherein the first valve seat and the second valve seat extend between same radially inner and radially outer distances of the axis. 
     
     
         17 . A drain valve comprising a rigid post member having an engagement formation for attachment to a drain valve housing structure, the post member having one or more valve membranes in the form of a skirt molded thereon such that the skirt valve is fused or otherwise integrally formed onto the rigid post member, the skirt valve being of a softer material than the rigid post member. 
     
     
         18 . The drain valve according to  claim 17 , wherein the rigid post member comprises a first engagement formation at one end thereof for mounting the rigid post member to the housing structure and a further engagement formation at an opposing end thereof for attachment to a further post, at least one valve member being mounted to the rigid post member in between the first engagement formation and the second engagement formation. 
     
     
         19 . The drain valve according to  claim 17 , wherein the one or more valve membranes comprise a resilient elastomeric material and have a central collar portion and a peripheral skirt depending radially outwardly from the collar portion, the skirt being arranged to yield in response to a presence of a liquid thereon in use, wherein the skirt comprises one or more regions of weakness to promote a folding action of the skirt upon yielding. 
     
     
         20 . The drain valve according to  claim 19 , wherein the one or more regions of weakness comprises one or more elongate radial grooves and an annular groove proximal the collar portion. 
     
     
         21 . The drain valve according to  claim 19 , wherein the one or more regions of weakness comprises a plurality of areas of weakness depending outwardly from the collar portion, said areas being substantially equally angularly spaced about the collar portion. 
     
     
         22 . The drain valve according to  claim 17 , wherein the one or more valve membranes comprise one or more portions being arranged to change color over a period of valve use.